Motor Vehicle Parts Manufacturing (United States) — NAICS 3363

A Histometrics industry-group primer for public-market and private investors

This is a real rollup. NAICS (the North American Industry Classification System, the federal standard for sorting businesses by activity) code 3363 is a four-digit industry group, and unlike its children it genuinely aggregates eight distinct five-digit industries — engines, electrical/electronic gear, steering and suspension, brakes, transmissions, seating, metal stampings, and an "everything else" bin. Each child happens to be a one-to-one pass-through to a single six-digit industry, so the child primers read almost identically; the value this page adds is the contrast across the eight — which are big, which are shrinking, who owns them, and how you can (or cannot) buy them. Read this to see the whole board; read a child primer for one square.

The eight children have since been rebuilt on independent company-level sourcing — SEC filings, foreign annual reports, and federal series newer than the 2022 census — so this page now carries measured margins, quantified customer and tariff exposure, a materially changed regulatory picture, and several corrections the earlier version got wrong.

1. Overview

NAICS 3363 is the U.S. independent auto-parts factory base: the roughly 4,659 plants and 587,000 workers that make the components an automaker bolts onto a vehicle it assembles [1][2]. If you think of the car industry as assembler-plus-suppliers, this industry group is the suppliers — a ~$278 billion-a-year manufacturing base that sits one tier below the brands and sells into two channels: original equipment (OE — parts sold to automakers for new vehicles) and the aftermarket (replacement parts for the ~289 million vehicles already on U.S. roads) [1][4].

Why an investor should care: this is one of the largest, most cyclical, and most contested corners of American manufacturing. It rides the auto-production cycle, it is being reordered by the shift to electric vehicles (EVs — battery-powered cars that need no engine, transmission, or exhaust), and it is absorbing a tariff regime aimed squarely at its cross-border supply chain [32][33]. Three things moved since this page was last written, and all three cut in the same direction. The EV transition decelerated — U.S. EV share was flat-to-down in 2025 versus 2024, and hybrids hit a record share in 2026 [37]. The federal electrification mandate was withdrawn — the Environmental Protection Agency (EPA) rescinded the vehicle greenhouse-gas standards in February 2026, though the traditional air-pollutant rules that create catalytic-converter demand were left intact [29]. And the trade backdrop hardened — at the scheduled July 2026 review the administration declined to extend the U.S.-Mexico-Canada Agreement (USMCA) in its current form [34]. Together these lengthen the runway for the combustion-exposed children and raise, not lower, the planning uncertainty for everyone.

Crucially, none of this hits the eight children the same way: some are structural winners, some are in managed decline, and some barely care what powers the car. That divergence — not any single headline number — is the investment story at this level.

2. What's inside — and how the eight children differ

NAICS nests from broad sector (2-digit) to subsector (3-digit, here 336 = Transportation Equipment Manufacturing) to industry group (4-digit, 3363) to industry (5-digit) to national industry (6-digit). The 3363 group holds eight five-digit industries. Each contains exactly one six-digit child, so at the leaf level "33631 = 336310," and so on — but the eight are genuinely different businesses.

The single most useful thing this page can give you is a side-by-side. Ordered largest to smallest by U.S. shipments:

* HHI = Herfindahl-Hirschman Index, a 0–10,000 market-concentration score; the U.S. Department of Justice treats readings below ~1,500 as "unconcentrated." CR4 is the share of shipments held by the four largest firms. All figures are our ground-truth federal statistics for each child [1][2]; per-child sources are in each child primer.

Six axes of difference worth internalizing:

1. Size. The largest child (Other Parts, $66.5B) is more than six times the smallest (Brakes, $10.2B). The top three — Other Parts, Transmission, and Stamping — are more than half the whole group [1].
2. EV exposure — still the biggest differentiator, but the clock slowed. Sort the eight by how electrification treats them and you get three buckets. Winners: electrical/electronic equipment and the thermal-management slice of Other Parts. Losers: gasoline engines, exhaust and catalytic converters, multi-speed transmissions, and brake-pad volume. Neutrals: steering, suspension, seating, and — with a lightweighting caveat — metal stamping, because a car still has to steer, seat people, and have a body whatever powers it. What changed is the pace: U.S. EV share did not rise in 2025, hybrids did, and the children's own numbers differ on the level depending on definition — roughly 6–10% of 2025 sales depending on whether plug-in hybrids count and whether the denominator is cars or all light-duty vehicles [37]. Battery-electrics were only 2% of the registered U.S. fleet in the latest data, which is why the aftermarket-heavy children are insulated for decades regardless [37].
3. Concentration — and the CR4 tells you more than the HHI. Every child is technically "unconcentrated" by HHI, but the top-heaviness varies enormously: engines (CR4 45.7%), seating (40.7%), transmission (39.5%), and brakes (38.4%) are dominated by a handful of large plants, while stamping (23.5%) and Other Parts (13.6%) are genuinely fragmented [1]. The federal numbers also flatter fragmentation: in brakes, the five largest global suppliers hold an estimated 60–65% of the world market and 70–75% of friction products, invisible in U.S. establishment data [41].
4. Ownership and access. Three children now have a U.S.-listed near-pure-play you can actually buy — transmission (Allison, Dana, Dauch), seating (Adient, Lear), and, new since April 2026, electrical via Versigent, the wiring-harness business spun out of Aptiv [18]. Brakes gained a partial route in ITT, whose Motion Technologies segment is the one domestically listed way to own actual friction manufacturing [22]. The rest are dominated by foreign-listed Tier-1 suppliers (a "Tier-1" sells finished systems straight to the automaker), automaker captive plants, or private-equity and family owners.
5. Aftermarket cushion. Brakes and engine parts throw off large, recession-resistant replacement revenue — in brakes, OE is only about 30–35% of the market and the independent aftermarket 55–60% [41]. Seating throws off almost none; seats are rarely replaced [8]. That single fact makes brakes far less cyclical than its OE-heavy peers despite being the smallest child.
6. Measured profitability — and it does not sort by child. The children now supply real company margins, and the spread inside a single industry is wider than the spread between industries: Allison earns a 37.5% adjusted EBITDA margin while Dana earns 8.1%, both inside transmission [12][13]. Section 5 has the detail; the takeaway is that defensibility, not product category, sets the return.

For product scope, exclusions, and company tables, follow the link to any child primer (33631 engines, 33632 electrical, 33633 steering/suspension, 33634 brakes, 33635 transmission, 33636 seating, 33637 stamping, 33639 other).

3. Size — the group rollup

These are our ground-truth federal figures for the whole of NAICS 3363. They reconcile exactly to the children: the eight child shipment figures sum to $278.3B, the eight employment figures to 587,237, the eight establishment counts to 4,659, and the eight payrolls to $36.3B [1][2].

That works out to roughly $60 million of shipments and about 126 workers per plant, at an average wage near $62,000 — mid-to-large capital-intensive factories, not owner-operators [1][2].

The one number the rollup reveals: dispersion. The group HHI of 102.2 is lower than every individual child's — the most fragmented child, Other Parts, is already 125.4 [1]. (One correction the child data forces: the group's CR4 of 14.3% is not lower than every child's, as this page previously implied; Other Parts is marginally more fragmented still at 13.6% [1].) The HHI result is not a rounding quirk — it is the central structural fact of this level: the leaders differ by product line. The company that dominates brakes is not the one that dominates seating or wiring, so pooling the eight dilutes concentration further. Across the entire ~$278 billion parts sector, the four largest firms hold barely one dollar in seven, and no single supplier comes close to controlling it. Power in this industry is real but local to a product aisle, not sector-wide.

Newer employment data says the base is shrinking — but do not add it up. The 587,237 above is the 2023 County Business Patterns establishment count, and it is the only figure that legitimately rolls to a group total. Four children now also carry a Bureau of Labor Statistics (BLS) payroll series, and where it is comparable it points down: engines fell from 61,615 in 2023 to 52,700 in May 2026, electrical from 60,662 to about 57,700 in 2025, and transmission from 85,065 to 74,600 in May 2026 [2][3]. Stamping is the cautionary case: BLS reports about 84,400 jobs against CBP's 106,098, and the stamping child is explicit that this is a measurement-concept gap, not a decline [3]. So read the direction, not the decimal, and never sum the two series — they are differently constructed and differently dated.

Undercount and reconciliation caveats. This is a well-counted field — established, payroll-filing plants, not the sole-proprietor or informal activity the census tends to miss — so the usual small-ownership undercount is minimal. The distortions run the other way, and they are large:

• Imports. These are U.S. production figures. The country installs far more parts than it makes and is a net importer across most of the eight children [40]. The brakes child now puts a number on the gap: about $10.2 billion of domestic shipments against an estimated $22–26 billion of U.S. brake consumption including imports and distribution margins [41]. Assume a similar wedge elsewhere.
• Captive activity sits outside the code. Automakers stamp body panels and build engines in-house, and those captive plants are generally classified under vehicle assembly (NAICS 336110/336111), not here. Both the stamping and engine children flag this as the dominant distortion in their categories, so this group understates the true footprint of "making car parts in America" most acutely there.
• The scope is not purely automotive, in either direction. The seating child's research establishes that Census cross-references aircraft seats into 336360, so that $29.9 billion is wider than the automotive seating market [45]. The electrical child cuts the other way: bulbs, storage batteries, EV traction motors, infotainment head units, and semiconductors all sit in other codes, so its $28.0 billion is far narrower than "automotive electronics," which broader estimates put near $62 billion for 2024. Treat the group total as a classification artifact, not a market.
• Foreign and private parents dwarf the U.S. plant data. Many of the largest players are foreign-owned (Bosch, Denso, ZF — 93.8% held by the Zeppelin Foundation [24] — Aisin, Valeo, Forvia, Yazaki), family/foundation-held (Mahle), or private-equity-controlled (Tenneco under Apollo, Marelli under KKR). Scale check: Tenneco alone carried roughly $18 billion of global revenue, 71,000 employees, and 260-plus sites at the time of its buyout [27] — a single private company larger than several of these children, though that is company-global revenue and is not comparable to U.S. shipments.
• Firms vs. establishments. The eight child firm-counts sum to 4,008, but the group reports 3,814 distinct firms [1]. The ~200 gap is diversified suppliers — a BorgWarner, a Dana, a Magna — counted once at the group level but appearing in several children. It is a useful reminder that the same handful of big suppliers straddle multiple boxes in the table above.

4. Investable universe — where value concentrates across the children

The defining fact of this level is unchanged: there is no pure-play for the group. What changed is the count of children where a listed U.S. equity maps onto one industry — it has gone from two to three, plus a partial fourth.

• Diversified, multi-child Tier-1 suppliers are how public investors touch the most ground at once. A short list recurs across the table — BorgWarner (engines, electrical, transmission; ~$14.3 billion of FY2025 sales, split 82% combustion-and-hybrid "Foundational" to 18% eProducts) [17], Dana and Dauch (steering/suspension + transmission), Magna (stamping + seating + more; ~$42 billion, with Body Exteriors & Structures at $16.6 billion and Seating Systems at ~$5.9 billion) [10], Aptiv ($20.4 billion) [18], Autoliv ($10.8 billion of belts and airbags) [9], Modine (thermal, ~$2.6 billion) [26]. Buying one of these buys a basket of the eight, weighted to its mix.
• Near-pure-plays now exist in three children. Transmission and power train offers Allison, Dana, and Dauch Corporation — note the ticker change: American Axle became Dauch (DCH) on completing the Dowlais combination in February 2026, so AXL no longer trades [14]. Seating offers Adient (a seating pure-play at ~$14.5 billion of sales, ~200 plants in 29 countries and the global leader on roughly 32% share) and Lear (seating is $17.3 billion of ~$23 billion, on a management-estimated 26% of global complete-seat revenue) [7][8]. Electrical now offers Versigent (VGNT), the wiring-harness business separated from Aptiv on April 1, 2026 and the closest thing to a listed pure-play in that child [18].
• Brakes gained a partial U.S. route. The child research identifies ITT Inc., whose Motion Technologies segment — passenger-car brake pads alongside shocks and rail — did $1.428 billion of 2025 revenue at a 19.3% operating margin [22]. It is not a pure-play, but it is the one domestically listed way to own friction manufacturing rather than friction distribution.
• Foreign-listed and private owners still hold most of the tonnage. Brakes runs through Brembo (€3.7 billion, the nearest public pure-play), AUMOVIO — Continental's braking and automotive business, separately listed since its spin-off completed in September 2025 [23] — Knorr-Bremse (owner of Bendix), and Aisin [21]. Steering runs through Nexteer (~$4.6 billion, 68% of revenue from electric power steering, majority-controlled by a Chinese state group) [20], JTEKT, thyssenkrupp, and HL Mando. Electrical runs through Bosch, Denso, Yazaki, and Sumitomo. Stamping runs through Gestamp (€11.3 billion) and voestalpine plus private-equity and family shops [11]. Private equity is a first-class owner across the whole group — Apollo's Tenneco alone spans engines, brakes, steering, and exhaust [27].

The practical takeaway: the public market shows you only a slice of NAICS 3363, tilted toward the diversified and the aftermarket; the private and foreign-owned majority is where most of the industry actually trades hands.

5. How the money works

The economics are the same across all eight children, which is why one framework travels: this is cyclical, capital-intensive manufacturing, not a subscription or a brand. The revenue identity is

content per vehicle (CPV) × vehicle production volume, plus aftermarket sales.

• Volume ties earnings to the auto-production cycle. Plants carry heavy fixed costs (presses, dies, casting, machining lines), so when they run full, fixed cost spreads over more units and margins expand fast; when automakers cut builds, the same costs crush margins. Contract structure offers thinner protection than it looks: OE agreements typically cover a customer's requirements without any minimum purchase quantity, and just-in-time delivery means a stoppage anywhere on the chain halts a line quickly [17].
• Content per vehicle is the structural growth lever, and it is the only way to grow when U.S. build volumes are flat. Selling more dollars of parts per car — an all-wheel-drive system instead of a plain axle, a heated-and-ventilated seat, more electronics, bigger wheels — lets a supplier outgrow a stagnant unit market. Suppliers track it as a backlog of program wins.
• Margins are thin on average — and the dispersion is enormous. The average global auto supplier earned an operating (EBIT — earnings before interest and taxes) margin of roughly 4.7% in 2024 [38], and that average now looks close to useless. The children's measured figures run from about 2% to about 37%. On the high side: Allison 37.5% adjusted EBITDA on $3.010 billion [12], Gentex a 34.7% gross margin and ~19% operating margin [19], ITT 19.3% [22], Brembo 16.5% EBITDA / 9.1% EBIT [21], Knorr-Bremse's commercial-vehicle division 14.7% / 9.1% [21], Nexteer 11.4% gross and ~10% adjusted EBITDA (but only 2.2% net) [20], Autoliv 10.1% operating [9]. On the low side: Magna's stamping segment 8.1% adjusted EBIT [10], Dana 8.1% [13], Adient 6.6% gross against ~6.1% adjusted EBITDA [8], Martinrea 5.6% [11], Lear's seating segment 5.5% [7], Magna Seating 3.6% [10], Lear's E-Systems (wiring) 3.1%, down from 4.1% [7], and Superior Industries about 2.3% operating on an 8.7% gross margin [26]. These are not like-for-like — gross, EBITDA, EBIT, operating and net margins are mixed, and each includes foreign operations and adjacent products — so read them as bounds, not as the industry's margin.
• The dispersion sorts by defensibility, not by child. This is the rollup's sharpest new finding. The widest gaps sit inside a single industry, not between industries: Allison's 37.5% against Dana's 8.1% is one child, and the difference is a protected commercial-truck franchise with high switching costs and multi-year agreements versus contested, electrification-exposed light-vehicle driveline work [12][13]. Same story in electrical, where Gentex's 34.7% gross margin sits next to Lear's 3.1% wiring-harness segment [7][19]. One outlier deserves a footnote: Dorman's 42.1% gross and 14.1% operating margins are the highest here, but Dorman designs and sources rather than manufactures much of its catalog, buying about 77% of product outside the U.S. and 38% from China [25] — a different business model, not a better factory.
• The aftermarket is the steadier, higher-margin cousin. Replacement demand tracks the size and age of the fleet, not new-car production, and is effectively counter-cyclical. Brembo's 2025 results are a live demonstration: passenger-car OE sales fell 5.2% and commercial-vehicle OE fell 10.5%, with aftermarket performance partly offsetting [21]. Its weight varies enormously by child (large in brakes and engine parts, negligible in seating), which is the single biggest reason the eight have such different cyclicality.
• Inputs pass through, but on the automaker's terms and timing. Materials dominate the cost base — 66% of Allison's cost of sales [12], about 65% of Nexteer's revenue [20], roughly 54% of Autoliv's sales [9], and more than 60% of cost in stamping. The pass-through is more structured than a simple lag: Magna reports roughly two-thirds of its combined steel and aluminum purchases run through OE resale programs negotiated by the automaker, with the balance on annual or index-linked contracts [10]. Superior's aluminum contracts are indexed, yet customer price adjustments rarely land when costs move, so pass-through smooths revenue more reliably than it smooths gross profit [26]. Precious-group metals (PGMs — platinum, palladium, rhodium) drive catalytic-converter cost, and rhodium above $11,000 an ounce in 2026 inflates working capital and invites theft.

The dials to watch are capacity utilization, OE-versus-aftermarket mix, margin net of commodity pass-through, new-program award backlog, and free cash flow against debt. Cash matters more than accounting profit in the thin-margin children: Adient generated $204 million of free cash flow and returned $125 million through buybacks in fiscal 2025 while posting a net loss [8].

6. Demand drivers

The eight children share four master drivers; what differs is which one dominates each:

• Volume — and be precise about which volume. The children measure it three different ways, and the numbers are not interchangeable. U.S. sales: NADA puts 2025 U.S. light-vehicle sales at 16.2 million [5], though the stamping child cites roughly 15.3 million for the same year and a 15.9-million seasonally adjusted annual rate (SAAR) in April 2026 [6] — a genuine disagreement across the children worth flagging rather than averaging. North American production, the right measure for OE suppliers whose plants sit across the USMCA bloc: 15.29 million units in 2025, down about 1% from 2024 [7], against 16.06 million in 2024 on a comparable basis [20]. U.S. assemblies alone: near a 10.0-million annual rate in 2025 versus 10.2 million in 2024. OE demand tracks vehicles built, not sold — the U.S. imports finished cars, so sales overstate the domestic build.
• The installed fleet (the aftermarket floor). About 289 million vehicles are in operation at a record average age of 12.8 years in 2025 — passenger cars at 14.5 years, the fleet up 3 million units, scrappage at 4.5% [4]. An old, large fleet is a durable, recession-resistant tailwind for the replacement-heavy children (brakes, engine parts, steering). Brake pads wear on a 25,000–65,000-mile cycle, which is non-deferrable maintenance [42].
• Content per vehicle. Safety mandates, electrification, driver-assist systems (ADAS — advanced driver-assistance systems), and premiumization all push more dollars into each car. Electronic content is projected toward 35–40% of total vehicle value by 2035 [39]; electric power steering is already on more than ~70% of North American new vehicles and over 85% of battery-electrics [20]; and mix helps too, with crossovers and SUVs at about 49% of global production in 2025 against 40% five years earlier [7].
• The EV mix — a two-sided force that is running slower than forecast. Electrification roughly doubles electronic content and adds battery cooling (helping electrical and thermal), while erasing the engine, multi-speed transmission, and tailpipe and cutting brake-pad wear. But the transition decelerated: U.S. EV share was 9.4% of 2025 new light-vehicle sales, down from 9.8% in 2024, with the federal consumer tax credit ending September 30, 2025; the International Energy Agency's read is similar (~1.5 million U.S. sales, just under 10% of car sales, slightly below 2024) [37]. What is rising instead is hybrids, which reached a record 16% of U.S. sales in the second quarter of 2026 against battery-electrics at 6% and plug-in hybrids at 1.4% [37]. Hybrids are the swing fact for this group: they preserve engine, transmission and exhaust content while adding electrical, power-electronics and gearing content — a bridge, not a cliff.

7. Regulation

There is no economic price regulator here; the regulatory forces are safety, emissions, and — most acutely — trade. All three moved.

• Safety rules create demand. The National Highway Traffic Safety Administration (NHTSA) writes the Federal Motor Vehicle Safety Standards (FMVSS) that mandate this group's safety hardware — seat belts and airbags (FMVSS 207/208/209/210), braking (FMVSS 105/135/121), and the 2024 rule (FMVSS 127) requiring automatic emergency braking on essentially all new light vehicles, with compliance required by September 1, 2029; NHTSA projects at least 360 lives saved and 24,000 injuries prevented annually. The rule is under administrative review with appeals held in abeyance, but the 2029 deadline currently stands [31]. Regulation is a tailwind for the safety-content and electronics children. One nuance the brakes child adds: pads are not individually "FMVSS approved" — the standards govern vehicle braking systems and manufacturers self-certify.
• The federal emissions mandate was withdrawn — and that cuts both ways. In February 2026 the EPA finalized the rescission of the greenhouse-gas endangerment finding and the vehicle GHG standards that depended on it, while stating that traditional-air-pollutant requirements were not removed [29]. That last clause matters at this level: the rules that create catalytic-converter demand are the pollutant rules, not the climate rules, so the exhaust business is not directly hit by the rescission. NHTSA's 2024 Corporate Average Fuel Economy (CAFE) rule (about 2% per year for model years 2027–2031) remains the published final rule, but a replacement was proposed in December 2025 and had not been finalized as of mid-2026 [30]. The net for owners: the most binding federal push toward electrification is gone, extending the runway for the combustion-exposed children — but tighter rules were also what forced efficiency hardware onto each vehicle and raised supplier dollar-content, so relief is not unambiguously good for content growth, and repeated reversals shorten planning visibility for tooling that outlives an administration.
• Trade policy is the biggest live wildcard. In 2025 the U.S. imposed Section 232 tariffs of 25% on imported vehicles and many parts (parts effective May 3, 2025), with partial relief for U.S. content under USMCA; Section 301 and other duties stack on Chinese-origin parts, pushing effective rates on some Chinese rotors toward ~60% [32]. Separately, Section 232 tariffs on imported steel and aluminum were raised from 25% to 50% in June 2025, and the domestic-assembly offset credit steps down from 3.75% of qualifying U.S.-assembled vehicle MSRP through April 2026 to 2.5% through April 2027 [33]. Because so much of this group's labor-intensive and metal-intensive work is done in Mexico and Canada, the regime hits its cost base directly — USMCA qualification turns on regional value content of 75% for passenger vehicles and light trucks, 70% for principal parts, and 65% for complementary parts including catalytic converters [34]. And the biggest change since this page was last written: at the scheduled July 2026 USMCA review the administration declined to extend the agreement in its current form, leaving the rules that govern the group's cross-border footprint unresolved [34].
• A newer, less-discussed constraint: the connected-vehicle rule. The Commerce Department's Bureau of Industry and Security restricts covered vehicle software linked to China or Russia beginning with model year 2027 and covered connectivity hardware from model year 2030 (non-model-year hardware from January 1, 2029), with compliance declarations required of importers and manufacturers [35]. It advantages compliant North American suppliers while raising provenance, audit, and redesign costs — a direct hit to the electrical child and a growing one elsewhere as more parts become connected.

8. Consolidation

The through-line is consolidation and re-sorting, driven by one logic: spread expensive EV-drive and electronics R&D over more volume, and separate the declining internal-combustion assets from the growth-EV assets. Four patterns recur:

• Private-equity roll-ups. Apollo took Tenneco private in a ~$7.1 billion deal in 2022 — a business with roughly $18 billion of revenue, 71,000 employees, and more than 260 sites, spanning engine, brake, steering, and exhaust brands [27]; KKR holds Marelli (electrical); Panasonic's automotive-systems arm passed into private hands in 2024–2025. In stamping the pattern is distress-driven: Tower International (~$1.6 billion of revenue) went to Autokiniton/KPS at $31 a share in 2019, and Shiloh Industries' assets were bought out of Chapter 11 by MiddleGround Capital for about $400 million in 2020–21. Private capital, comfortable underwriting managed decline for cash flow, is the natural owner of the ICE-exposed and commoditized lines.
• Scale mega-mergers — one now closed. American Axle's combination with UK-listed Dowlais (GKN Automotive and GKN Powder Metallurgy) completed in February 2026, and the company now trades as Dauch Corporation (DCH): roughly $12 billion of combined revenue, ~$300 million of targeted annual synergies, operations across two dozen countries [14][15]. Note a genuine disagreement across the children on price — the steering primer carries the ~$1.44 billion announced cash-and-stock figure, while the transmission primer reports total consideration of approximately $1.7 billion [14][15]; we have not reconciled the two. Separately, Allison Transmission bought Dana's off-highway business for ~$2.7 billion, pushing Allison into construction, agriculture, and mining drivetrains while letting Dana refocus on light and commercial vehicles [16].
• Spin-offs to sharpen focus — all three now complete. BorgWarner carved out PHINIA (fuel systems/aftermarket, 2023); Continental completed the spin of its braking and automotive business into standalone AUMOVIO in September 2025 [23]; Aptiv completed the separation of its wiring harness as Versigent on April 1, 2026 [18]; Johnson Controls spun out Adient (seating, 2016). The aim is to let high-multiple electronics and ADAS growth trade apart from cash-generative but declining legacy hardware.
• Mistiming the transition is expensive in both directions. The clearest new evidence is ZF's €2.1 billion loss in 2025, driven by an e-mobility impairment charge tied to ending projects whose slower-than-expected EV adoption would not support expected profitability [24]. Set against a decade of warnings about investing too late, it is the counter-example this level needs: in an industry with multi-year tooling cycles, building electrification capacity ahead of demand destroys as much capital as building it behind.

The cautionary counter-example on financing is First Brands, a leveraged aftermarket roll-up in the Other-Parts space that collapsed into Chapter 11 in September 2025 with more than $10 billion of liabilities, followed by fraud charges against its executives in 2026 — a reminder that capital structure and disclosure quality matter as much as the parts [28]. Consolidation here is financed both well and badly.

9. Risks

The group's risks are shared, but their weight varies by child:

• Cyclicality and operating leverage — earnings amplify every swing in vehicle production. The stamping child now supplies the sharpest available measure of the amplitude: real sectoral output for that industry fell 20.2% in 2008 and 29.7% in 2009, rebounded 43.7% in 2010, then fell another 14.7% in 2020 [46]. Heaviest in the OE-concentrated children (stamping, seating, transmission).
• EV bifurcation — and mistiming in either direction. The defining structural risk, and it is asymmetric: existential for engines, exhaust, and multi-speed transmissions; a volume headwind for brakes; a tailwind for electrical and thermal; largely neutral for steering, suspension, and seating. What the revised children add is that the timing risk runs both ways — ZF's €2.1 billion loss for building too early [24] sits alongside the stranded-tooling risk of building too late.
• Customer concentration and price-downs — now quantified, and severe. A few automakers buy most OE output and impose annual price cuts across all eight children. The numbers: Dana's ten largest customers were 76% of 2025 sales and BorgWarner's 71% [13][17]; at legacy American Axle, GM, Ford, and Stellantis alone were 44%, 15%, and 13% [14]; General Motors was 34% of Nexteer's 2025 revenue [20]; Autoliv's five largest customers were ~44% and its ten largest ~70% [9]; Aptiv's top ten were ~56% [18]; GM, Ford, VW, and Toyota were 24%, 16%, 12%, and 12% of Superior's sales [26]. Supplier concentration tells you who makes the output; customer concentration tells you how few buyers stand between these companies and a revenue shock.
• Commodity and input costs — steel, aluminum, copper, resin, and precious-group metals pass through with a lag, so spikes squeeze suppliers first; rhodium above $11,000 an ounce in 2026 is the extreme case.
• Tariffs and Mexico/Canada concentration — quantified. The 2025 Section 232 regime added an estimated ~$30 billion of cost across the auto industry, and in a March 2025 survey of 139 suppliers more than 80% reported exposure to steel or aluminum derivative tariffs [36]. Company-level: BorgWarner booked $108 million of incremental tariff expense on approximately $918 million of imports, 68% of that value originating in Mexico [17]; unrecovered tariffs cost Gentex about 110 basis points of gross margin in 2025 [19]. Note the accounting quirk Lear flags: tariff recoveries can protect profit dollars while diluting percentage margins, because reimbursement raises revenue without adding gross profit [7]. The unresolved USMCA review compounds all of it [34].
• Technology substitution that moves value without changing a single build. A cross-cutting risk the children now make explicit and the parent previously lacked. In stamping, large-format aluminum gigacasting can replace assemblies once built from many stamped and welded pieces [44]. In electrical, the software-defined vehicle consolidates distributed control units into domain or central computers with zonal wiring, threatening vendors of stand-alone modules while rewarding systems and connector suppliers. In seating, OEM insourcing and modular awards replacing complete-seat purchasing shift profit between participants [7]. Magna itself notes automakers may insource components to protect employment commitments as electric powertrains eliminate other mechanical content [10].
• Leverage — debt-heavy private-equity structures are common; First Brands is the live warning [28].
• Recall and product-liability tail — outsized on safety-critical parts (brakes, airbags, seat belts, steering), and it carries a real balance-sheet cost: Nexteer alone held $84.1 million of estimated warranty and product-liability provisions at year-end 2025 [20]. The Takata airbag recall is the permanent reminder.

10. How to invest, and the outlook

Public routes. Because there is no group-level pure-play, public investors choose a lens:

• Diversified Tier-1 exposure — BorgWarner (BWA), Magna (MGA), Aptiv (APTV), Dana (DAN), Dauch (DCH) — one ticker, a basket of children.
• The three near-pure-play children — transmission via Allison (ALSN), Dauch (DCH) and Dana (DAN); seating via Adient (ADNT) and Lear (LEA); electrical wiring harness via Versigent (VGNT). If you hold an old note that says AXL, it is now DCH [14][18].
• The EV-winner tilt — electrical/electronics names (Aptiv, Sensata, Visteon, Gentex) and thermal management (Modine) for the content-growth theme [19][26].
• Friction and safety content — ITT (ITT) is the one U.S.-listed route into brake manufacturing; Autoliv (ALV) is the restraints franchise at ~44% of the global airbag and ~45% of the seat-belt market, and is largely insulated from the EV-versus-combustion argument because every vehicle needs restraints [9][22].
• The aftermarket, lower-cyclicality tilt — Dorman (DORM), Standard Motor Products (SMP), and the parts retailers/distributors (Genuine Parts, O'Reilly, AutoZone, Advance Auto Parts) that profit from the 289-million-vehicle fleet without manufacturing [4][25].
• Index-style — broad auto-supplier exchange-traded funds (ETFs, e.g. First Trust's global auto fund, ticker CARZ) give sector exposure but blur the winner/loser split that is the whole point of Section 2.

Because these are cyclicals, judge valuation multiples across a full auto cycle rather than at a peak or trough, and note that capital return skews toward buybacks over rich dividends — Adient repurchased about 7% of its shares in fiscal 2025 while running a net loss [8].

Private routes matter as much or more. The majority of NAICS 3363 by value is private-equity-owned, foreign-owned, or family-held. Private capital participates through Tier-1 buyouts (Apollo/Tenneco, KKR/Marelli), aftermarket and remanufacturing roll-ups, and the long tail of privately held forging, machining, casting, and cut-and-sew shops — plus private credit lending to those platforms, where First Brands is a standing warning on leverage and disclosure [27][28]. The children converge on the same diligence discipline, and it is program-level rather than company-level: separate OE from aftermarket revenue, measure platform and customer concentration, identify customer-owned versus supplier-owned tooling, test commodity pass-through timing and country-of-origin exposure, quantify warranty history and recall indemnities, price environmental liabilities at older foundry and friction sites, and check whether capitalized engineering is recoverable if a program slips. And never accept a seller's "powertrain" or "chassis" revenue as equivalent to a NAICS code without a product-level bridge.

Outlook (forward-looking judgment). The right mental model is a mature, cyclical, consolidating industry group that is bifurcating underneath a flat surface — with the bifurcation now running slower than the 2024 consensus assumed. In aggregate, North American build volumes are flat-to-soft (~15.3 million units in 2025, down about 1%) and tariffs are a near-term drag [7][32]; the record-old fleet underpins a durable aftermarket floor [4]; and rising content per vehicle lets the best suppliers grow revenue even without more cars. The decisive variable is still the EV transition's pace and mix, which does not lift or sink the whole group but reallocates value across it — and on the current evidence it is reallocating more slowly and more hybrid-heavy than expected, which extends the runway for engines, exhaust, and multi-speed transmissions without changing their terminal direction [29][37]. The unresolved item is trade: with USMCA not extended in its current form at the July 2026 review, the cost base of a group that builds much of its labor- and metal-intensive work in Mexico and Canada is genuinely unsettled [34].

Own it selectively and by product line, not as a single buy-and-forget bet on "car parts" — and select on defensibility rather than category. The 35-point margin gap between Allison and Dana inside the same child says more about where to put money than any group average does [12][13].

For company-by-company scale, unit economics, and full sourcing on any square of the board, read the relevant child primer (33631, 33632, 33633, 33634, 33635, 33636, 33637, 33639).

---

Sources

Synthesized from the eight child primers (NAICS 33631–33639) and our ground-truth federal statistics for NAICS 3363.

1. U.S. Census Bureau, 2022 Economic Census — Industry Statistics and Concentration Ratios, NAICS 3363 and its eight children (group receipts $278.24B; 3,814 firms; CR4 14.3%, CR8 22.4%, CR20 37.2%, CR50 53.8%; HHI 102.2; per-child receipts, firm counts, CR4/CR8/CR20/CR50 and HHI). Histometrics ingested federal statistics. https://www.census.gov/programs-surveys/economic-census.html
2. U.S. Census Bureau, County Business Patterns 2023, NAICS 3363 and children (employment 587,237; 4,659 establishments; annual payroll $36.35B; Q1 payroll $9.45B; per-child employment, establishments and payroll). https://www.census.gov/programs-surveys/cbp.html
3. U.S. Bureau of Labor Statistics, industry employment series (engines 52,700, May 2026; electrical ~57,700 in 2025; transmission 74,600, May 2026; stamping ~84,400, November 2024). 2024–2026. https://www.bls.gov/ces/data/employment-and-earnings/2026/table1b_202605.htm; https://fred.stlouisfed.org/series/IPUEN336320W200000000; https://www.bls.gov/web/empsit/ceseeb1b.htm; https://www.bls.gov/ces/data/employment-and-earnings/2024/table1b_202412.htm
4. S&P Global Mobility, U.S. Vehicle Age Rises Again to 12.8 Years in 2025 (289 million light vehicles in operation; passenger cars 14.5 years; fleet up 3 million units; 4.5% scrappage; >16 million registrations in 2024). 2025. https://press.spglobal.com/2025-05-21-U-S-Vehicle-Age-Rises-Again-to-12-8-Years-in-2025,-According-to-S-P-Global-Mobility
5. National Automobile Dealers Association, December 2025 Market Beat (16.2 million U.S. light-vehicle sales in 2025). 2026. https://www.nada.org/nada/nada-headlines/december-2025-market-beat-new-light-vehicle-sales-totaled-162-million-units
6. National Automobile Dealers Association, Market Beat — New Light-Vehicle SAAR Hits 15.9 Million Units, April 2026 (2025 sales ~15.3M; Cox Automotive 2026 forecast ~15.8M). 2026. https://www.nada.org/nada/nada-headlines/nada-market-beat-new-light-vehicle-saar-hits-159-million-units-april-2026
7. Lear Corporation, Form 10-K, FY2025 (seating segment $17.3B at 5.5% margin, ~26% of global complete-seat revenue; E-Systems $5.976B at 3.1% margin vs 4.1% prior year; customer mix; North American production 15.29M units in 2025, down ~1%; crossovers/SUVs ~49% of global production; BEVs 16% of global output; tariff-recovery margin dilution). 2026. https://www.sec.gov/Archives/edgar/data/842162/000084216226000011/lear-20251231.htm
8. Adient plc, Fiscal 2025 Form 10-K (~$14.5B net sales; ~200 plants in 29 countries; 6.6% gross margin, ~6.1% adjusted EBITDA; $204M free cash flow; $125M buybacks, ~7% of shares; net loss; seating not largely affected by the powertrain shift). 2025. https://www.sec.gov/Archives/edgar/data/1670541/000167054125000152/adnt-20250930.htm
9. Autoliv, Inc., 2025 Form 10-K (sales $10.815B; 10.1% operating margin; ~44% global airbag and ~45% seat-belt share; direct materials ~54% of sales; top-5 customers ~44%, top-10 ~70%). 2026. https://www.sec.gov/Archives/edgar/data/1034670/000119312526058162/alv-20251231.htm
10. Magna International Inc., 2025 Annual Report and Form 40-F (Body Exteriors & Structures $16.618B at 8.1% adjusted EBIT; Seating Systems ~$5.9B at 3.6%; ~$42B group; ~two-thirds of steel/aluminum via OEM resale programs; competitor list; insourcing risk). 2026. https://www.sec.gov/Archives/edgar/data/749098/000110465926036223/tm2530886d7_ex99-1.pdf; https://www.sec.gov/Archives/edgar/data/749098/000119312526128771/d20215dex991.htm
11. Martinrea International, Q4 2025 Press Release (5.6% adjusted operating margin); Gestamp, Gestamp reports revenues of €11.3 billion in 2025 (€1.3B EBITDA). 2026. https://www.martinrea.com/wp-content/uploads/Q4-2025-Press-Release-March-5-2026.pdf; https://www.gestamp.com/Media/News/Press-Releases/2026/Gestamp-reports-revenues-of-€11-3-billion-in-a-challenging-market-environment-in-2025
12. Allison Transmission Holdings, Inc., 2025 Full Year Results and Form 10-K (net sales $3.010B; adjusted EBITDA $1.130B, 37.5% margin; cost of sales 66% materials / 26% overhead / 8% direct labor; multi-year agreements covering >90% of North American unit volume; ~1,500 distributor and dealer locations). 2026. https://www.sec.gov/Archives/edgar/data/1411207/000119312526063975/d105532dex991.htm; https://www.sec.gov/Archives/edgar/data/1411207/000119312526065627/alsn-20251231.htm
13. Dana Incorporated, 2025 Full Year Results and Form 10-K ($7.500B continuing-operations sales; adjusted EBITDA $610M, 8.1% margin; ten largest customers 76% of sales). 2026. https://www.sec.gov/Archives/edgar/data/26780/000119312526056030/d106316dex991.htm; https://www.sec.gov/Archives/edgar/data/26780/000143774926006076/dan20251231_10k.htm
14. Dauch Corporation (formerly American Axle & Manufacturing), 2025 Annual Report (Dowlais combination closed February 2026, total consideration ~$1.7B; ~$12B combined revenue; GM 44%, Ford 15%, Stellantis 13% of 2025 sales; Guanajuato and USMCA concentration risks). 2026. https://www.sec.gov/Archives/edgar/data/0001062231/000106223126000083/a26-aamx0035_2025annualrep.pdf
15. American Axle & Manufacturing, AAM Announces Combination with Dowlais for $1.44 Billion in Cash and Stock and Creating a Leading Global Driveline and Metal Forming Supplier investor presentation (~$12B combined revenue; ~$300M synergies). 2025. https://www.aam.com/media/story/aam-announces-combination-with-dowlais; https://www.aam.com/docs/default-source/transaction/rule-2-7-announcement/investor-presentation.pdf
16. FleetOwner, Allison acquires Dana's off-highway division for $2.7B. 2025. https://www.fleetowner.com/equipment/article/55296945/
17. BorgWarner Inc., Form 10-K, FY2025 and Fourth Quarter and Full Year 2025 Results (net sales ~$14.3B; 82% Foundational / 18% eProducts; top-10 customers 71% of sales; $108M incremental tariff expense on ~$918M of imports, 68% Mexico; gross margin 18.7%, GAAP operating margin 3.7%, adjusted operating margin 10.7%; Drivetrain & Morse Systems 18.4%; OEM contract terms and just-in-time dependence). 2026. https://www.sec.gov/Archives/edgar/data/908255/000090825526000011/bwa-20251231.htm; https://www.sec.gov/Archives/edgar/data/908255/000090825526000009/a20251231ex991pressrelease.htm
18. Aptiv PLC, 2025 Annual Report (revenue $20.4B; 12.1% adjusted operating margin; top-10 customers ~56% of sales) and Aptiv Announces Spin-Off of Electrical Distribution Systems (Versigent, NYSE: VGNT), completed April 1, 2026. 2026. https://www.sec.gov/Archives/edgar/data/1521332/000152133226000031/aptv12312025arsa.pdf; https://www.tradingview.com/news/tradingview:84c3760b4aac4:0-aptiv-plc-announces-spin-off-of-electrical-distribution-systems/
19. Gentex Corporation, 2025 Form 10-K and 2025 Results (sales $2.534B; ~19% operating margin; 34.7% gross margin; 79% global auto-dimming mirror share; top-3 customers 18%, 11%, 10%; ~110 bps gross-margin hit from unrecovered tariffs). 2026. https://www.sec.gov/Archives/edgar/data/355811/000035581126000010/gntx-20251231.htm; https://www.sec.gov/Archives/edgar/data/355811/000035581126000005/exhibit99112312025.htm
20. Nexteer Automotive Group Limited, 2025 Annual Report, Hong Kong Stock Exchange (~$4.6B revenue; 68% of revenue from electric power steering; 11.4% gross margin, ~10% adjusted EBITDA, 2.2% net margin; raw materials ~65% of revenue; GM and affiliates 34% of revenue; $84.1M warranty and product-liability provisions; EPS >70% of North American new vehicles and >85% of battery-electrics; North American production 16.06M in 2024). 2026. https://www1.hkexnews.hk/listedco/listconews/sehk/2026/0424/2026042402166.pdf
21. Brembo S.p.A., FY 2025 Results (revenue €3.703B; 16.5% EBITDA, 9.1% EBIT; passenger-car OE −5.2%, commercial-vehicle OE −10.5%); Knorr-Bremse AG, Commercial Vehicle Systems Division (2025: €3.503B revenue, 14.7% EBITDA, 9.1% EBIT; 2024: €3.842B). 2026. https://www.brembogroup.com/en/media/news/fy-2025-results; https://ir.knorr-bremse.com/en/company-information
22. ITT Inc., Form 10-K, FY2025 (Motion Technologies segment: $1.428B revenue, 19.3% operating margin). 2026. https://www.sec.gov/Archives/edgar/data/216228/000021622826000012/itt-20251231.htm
23. Continental AG, Notes — Discontinued Activities, 2025 Annual Report (AUMOVIO spin-off completed September 2025). 2026. https://annualreport.continental.com/2025/en/financial-statements/notes/discontinued-activities.php
24. ZF Friedrichshafen AG, 2025 Annual Report (€2.1 billion loss; e-mobility impairment charge) and Company Profile (Zeppelin Foundation 93.8% ownership). 2026. https://www.zf.com/mobile/en/company/annual_report/annual_report.html; https://www.zf.com/mobile/de/company/company.html
25. Dorman Products, Inc., 2025 Form 10-K (sales $2.130B; 42.1% gross margin; 14.1% operating margin; 77% of purchases from outside the U.S., 38% from China); Standard Motor Products, Inc., Fourth Quarter and 2024 Year-End Results and SMP Completes Acquisition of Nissens Automotive (~$1.46B revenue; Nissens ~$390M). 2025–2026. https://www.sec.gov/Archives/edgar/data/868780/000086878026000014/dorm-20251231.htm; https://www.smpcorp.com/newsroom/financial/smp-releases-fourth-quarter-and-2024-year-end-results/
26. Superior Industries International, Inc., FY2024 Form 10-K (revenue $1.267B; 8.7% gross margin; ~2.3% operating margin; GM 24%, Ford 16%, VW 12%, Toyota 12% of sales; aluminum pass-through timing; NYSE delisting, June 2025); Modine Manufacturing Co., FY2025 results (record net sales of $2.6 billion). 2025. https://www.sec.gov/Archives/edgar/data/95552/000095017025034599/sup-20241231.htm; https://www.sec.gov/Archives/edgar/data/67347/000155837025008029/tmb-20250520xex99d1.htm
27. Apollo Global Management, Apollo Funds Complete Acquisition of Tenneco (~$7.1B enterprise value) and Tenneco/Apollo completion announcement (2021 revenue ~$18 billion; 71,000 employees; 260+ sites). 2022. https://www.apollo.com/insights-news/pressreleases/2022/11/apollo-funds-complete-acquisition-of-tenneco-134627289; https://www.sec.gov/Archives/edgar/data/1024725/000119312522287303/d190359dex991.htm
28. U.S. Department of Justice, First Brands Executives Charged With Multibillion-Dollar Fraud (Chapter 11 September 2025, >$10 billion of liabilities; executives charged 2026). 2026. https://www.justice.gov/usao-sdny/pr/first-brands-executives-charged-multibillion-dollar-fraud
29. U.S. Environmental Protection Agency, Final Rule: Rescission of Greenhouse Gas Endangerment Finding and Vehicle GHG Standards (February 2026) and Fact Sheet (traditional-air-pollutant requirements remain). 2026. https://www.epa.gov/regulations-emissions-vehicles-and-engines/final-rule-rescission-greenhouse-gas-endangerment; https://www.epa.gov/system/files/documents/2026-02/420f26001.pdf
30. National Highway Traffic Safety Administration, Corporate Average Fuel Economy Standards for Model Years 2027 and Beyond (~2%/yr for MY2027–2031) and CAFE Standards Rulemaking Page (December 2025 replacement proposal; not finalized as of mid-2026). 2024–2026. https://www.federalregister.gov/documents/2024/06/24/2024-12864/corporate-average-fuel-economy-standards-for-passenger-cars-and-light-trucks-for-model-years-2027; https://www.nhtsa.gov/corporate-average-fuel-economy/final-rule-cafe-standards-mys-2027-2031-passenger-cars-and-light
31. Federal Register / NHTSA, FMVSS No. 127 — Automatic Emergency Braking Systems for Light Vehicles, Final Rule (compliance required September 1, 2029); NHTSA press release (at least 360 lives saved and 24,000 injuries prevented annually); Nelson Mullins, The Road Ahead for FMVSS 127 (administrative review; appeals in abeyance). 2024–2025. https://www.federalregister.gov/documents/2024/11/26/2024-27349/federal-motor-vehicle-safety-standards-automatic-emergency-braking-systems-for-light-vehicles; https://www.nhtsa.gov/press-releases/nhtsa-fmvss-127-automatic-emergency-braking-reduce-crashes; https://www.nelsonmullins.com/insights/blogs/driving-forward-developments-in-transportation-law-and-innovation/all/the-road-ahead-for-fmvss-127-whither-the-automatic-emergency-braking-mandate
32. Congressional Research Service, Section 232 Automotive Tariffs; The White House, Fact Sheet: Adjusting Imports of Automobiles and Automobile Parts (25% on imported vehicles and many parts, parts effective May 3, 2025; partial USMCA content relief); Plante Moran, Adjusting Automobile and Automobile Parts Tariffs (Section 301 stacking on Chinese-origin parts toward ~60% on some rotors). 2025. https://www.congress.gov/crs-product/IN12545; https://www.whitehouse.gov/fact-sheets/2025/03/fact-sheet-president-donald-j-trump-adjusts-imports-of-automobiles-and-automobile-parts-into-the-united-states/; https://www.plantemoran.com/explore-our-thinking/insight/2025/05/adjusting-automobile-and-automobile-parts-tariffs-action
33. BDO / Congressional Research Service, Section 232 Tariffs on Steel and Aluminum Doubled to 50% (June 2025); The White House, Amendments to Adjusting Imports of Automobiles and Automobile Parts (offset credit 3.75% of qualifying U.S.-assembled vehicle MSRP through April 2026, 2.5% through April 2027). 2025. https://www.bdo.com/insights/tax/section-232-tariffs-on-steel-and-aluminum-doubled-and-related-developments; https://www.whitehouse.gov/presidential-actions/2025/04/amendments-to-adjusting-imports-of-automobiles-and-automobile-parts-into-the-united-states/
34. Holland & Knight, Industry Stakeholders Discuss State of USMCA at USTR Hearing (July 2026 review; administration declined to extend USMCA in its current form); Office of the United States Trade Representative, USMCA Autos White Paper (75% regional value content for vehicles, 70% principal parts, 65% complementary parts including catalytic converters). 2019–2026. https://www.hklaw.com/en/insights/publications/2025/12/industry-stakeholders-discuss-state-of-usmca-at-ustr-hearing; https://ustr.gov/sites/default/files/files/Press/Releases/USTR%20USMCA%20Autos%20White%20Paper.pdf
35. Bureau of Industry and Security, U.S. Department of Commerce, Connected-Vehicle Rule (China/Russia software restrictions from MY2027, hardware from MY2030; non-model-year hardware January 1, 2029). 2025. https://www.bis.gov/press-release/commerce-finalizes-rule-secure-connected-vehicle-supply-chains-foreign-adversary-threats
36. Supply Chain Dive / Detroit News, Tariffs on steel and aluminum mean higher costs for the auto industry (~$30B of 2025 industry cost); Motor & Equipment Manufacturers Association, tariff survey (March 2025; 139 suppliers; >80% exposed to steel or aluminum derivative tariffs). 2025. https://www.supplychaindive.com/news/trump-tariffs-steel-aluminum-automotive-industry-production/739945/; https://www.mema.org/news/mema-statement-ongoing-impact-steel-and-aluminum-tariffs
37. Alliance for Automotive Innovation, Get Connected — EV Sales Dashboard (U.S. EV share 9.4% in 2025, down from 9.8% in 2024) and 2025 Q2 Get Connected (ICE ~74% of new U.S. sales vs >97% in 2016; federal EV tax credit ended 9/30/2025); U.S. Energy Information Administration, Today in Energy (electrified ~22% of 2025 light-duty sales, BEV 7.5%, PHEV 1.6%; BEVs 2% of the registered fleet in 2024) and U.S. light-duty vehicle sales by powertrain (Q2 2026: hybrids 16%, BEV 6%, PHEV 1.4%); International Energy Agency, Global EV Outlook 2026 (~1.5M U.S. EV sales in 2025, just under 10% of car sales and slightly below 2024). 2025–2026. https://www.autosinnovate.org/posts/papers-reports/stay-connected1-30-2026; https://www.autosinnovate.org/posts/press-release/2025-q2-get-connected-press-release; https://www.eia.gov/todayinenergy/detail.php?id=67144; https://www.eia.gov/todayinenergy/index.php/detail.php?id=50627; https://www.iea.org/reports/global-ev-outlook-2026/trends-in-electric-cars
38. Roland Berger / Lazard, Global Automotive Supplier Study (average industry EBIT margin ~4.7%). 2024. https://www.rolandberger.com/en/Media/Global-Automotive-Supplier-Study
39. Mordor Intelligence / IndexBox, Automotive Electronics Market — content per vehicle and ADAS/electrification outlook (electronic content toward 35–40% of vehicle value by 2035). 2025. https://www.mordorintelligence.com/industry-reports/automotive-electronics-market
40. Grand View Research / Mordor Intelligence, U.S. auto-parts and aftermarket market sizing (U.S. a net importer; consumption exceeds domestic production; OEM channel roughly two-thirds of parts value). 2025–2026. https://www.grandviewresearch.com/industry-analysis/aftermarket-automotive-parts-market
41. IndexBox, United States Automotive Brake System and Components Market (U.S. brake consumption ~$22–26B including imports and distribution margins; OE ~30–35%, independent aftermarket ~55–60%, OE service ~8–12%); MarketsandMarkets, Automotive Brake System / Brake Friction Products Market (top five suppliers ~60–65% of the world market, ~70–75% in friction). 2025–2026. https://www.indexbox.io/store/united-states-automotive-brake-system-and-components-market-analysis-forecast-size-trends-and-insights/; https://www.marketsandmarkets.com/ResearchInsight/automotive-brake-system-market.asp
42. Recharged, Brakes & Regenerative Braking in EVs (friction-pad wear cut up to ~80%; EV pads on the order of 100,000 miles; pads otherwise wear on a 25,000–65,000-mile cycle); U.S. Environmental Protection Agency, MOVES5 Technical Report — Brake and Tire Wear Emissions (68% reduction in brake-wear emissions from regenerative braking; friction brakes remain necessary and greater vehicle mass offsets part of the benefit). 2025. https://recharged.com/articles/brakes-regenerative-guide/; https://nepis.epa.gov/Exe/ZyPURL.cgi?Dockey=P101CTUW.txt
43. MarketsandMarkets / GMInsights, automotive exhaust-system market analyses (structural decline of ICE exhaust and catalytic converters, ~−3% a year through 2030 accelerating toward ~−8% by 2035; growth in EV thermal management); Transport & Environment, Cleaning up steel in cars (average steel content ~35% of vehicle weight in 2020 toward ~17% by 2050). 2023–2025. https://www.marketsandmarkets.com/Market-Reports/automotive-exhaust-system-market-87800437.html; https://www.transportenvironment.org/articles/cleaning-up-steel-in-cars-why-and-how
44. Magna International, Body-in-White Solutions (large-format casting / "gigacasting" substitution and the gigastamping response). 2025. https://www.magna.com/products/body-chassis/body-in-white-solutions
45. U.S. Census Bureau, 2022 NAICS Definition — 336413 Other Aircraft Parts and Auxiliary Equipment Manufacturing (cross-reference placing aircraft-seat establishments in 336360). 2022. https://www.census.gov/naics/?details=336413&input=336413&year=2022
46. U.S. Bureau of Labor Statistics / FRED, Industry Productivity: Real Sectoral Output for NAICS 336370 (−20.2% in 2008, −29.7% in 2009, +43.7% in 2010, −14.7% in 2020). 2025. https://fred.stlouisfed.org/data/IPUEN33637T011000000