Motor Vehicle and Motor Vehicle Parts and Supplies Merchant Wholesalers (NAICS 4231)

A Histometrics rollup primer — U.S. industry group. Relevant to both public-market and private investors.

1. Overview

NAICS (North American Industry Classification System) code 4231 is the industry group that sits one rung above four related wholesale industries: the middlemen who buy and resell whole motor vehicles, new parts, tires, and used/recycled parts at wholesale — moving product from manufacturers, insurers, and fleets to the dealers, repair shops, and yards that ultimately serve the driving public. (NAICS is the federal standard for sorting businesses; a four-digit code like 4231 is an "industry group" that aggregates several narrower industries.) It does not include retail motor-vehicle dealers or parts stores that sell to consumers — those live in the retail subsector (NAICS 441). [1]

For an investor, 4231 is a ~$1.07 trillion, high-throughput, thin-margin distribution complex tied to one of the economy's most durable demand streams: an American fleet of roughly 289 million light vehicles in 2025 — up about 3 million year over year, at a record average age of 12.8 years [6] — set against 297.5 million registered motor vehicles driven 3.294 trillion miles in 2024 [7], wearing out parts and tires and cycling through crashes, trade-ins, and off-lease returns. It is overwhelmingly a private-market business — the largest single whole-car operator in the group (Manheim) is privately held, and thousands of small independents make up the long tail — so the public investable universe is narrower than the industry's size suggests.

There are two reasons to read this level rather than jump straight to a leaf primer. The first is contrast: the four children look superficially alike (all are "wholesalers of vehicle stuff") but differ sharply in size, margin, growth direction, who owns them, and how the money is made. The second is scope: newer Census survey data now shows that a large share of the group's headline revenue is not independent middleman activity at all, but manufacturers' own sales branches — which shrinks the pool any private wholesaler can actually contest. Section 2 lays both out.

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

NAICS 4231 contains four industries. Each is a single-child "pass-through" (the five-digit code equals its lone six-digit national industry), so in practice the group is a clean four-way split. Here is the contrast, which is the point of this page:

Sources: shares from Histometrics' ingested federal receipts for 4231 [2]; ownership, direction, and how-to-invest synthesized from the child primers [8][10][11][12][13][14][18][19][22][23].

The federal numbers behind the contrast (each child's own ground-truth figures, per the child primers):

CR4 = share of receipts held by the four largest firms; HHI = Herfindahl-Hirschman Index, a standard concentration gauge where under 1,500 is "unconcentrated" and higher = more concentrated. [2][3] Gross margins are from the 2022 Economic Census margin-and-profit table, measured on sales made on the wholesaler's own account (for 42312, on independent merchant wholesalers) — a Census survey definition, not GAAP operating margin, EBITDA, or net income. [5] Revenue per employee for 42313 uses the $56.2 billion own-account basis its child primer now prefers. [3][5]

Where the children disagree — the tire revenue line. The 42313 primer now flags two different 2022 federal tabulations of the same code and does not reconcile them: Histometrics' ingested Economic Census extract carries $76.0 billion of receipts [3], while the Economic Census gross-margin table reports $56.2 billion of sales for merchant wholesalers on their own account [5]. The child now leads with $56.2 billion and treats the larger number as a differently-scoped tabulation. Because the ~7% share above is computed on the $76.0 billion basis that ties to the group total, read it as an upper bound; on the own-account basis the tire slice is smaller. Census separately suppressed the 2023 survey figure that would have covered all operating types for tires, so no complete tire total could be established. [4]

Four contrasts worth internalizing:

1. Revenue vs. jobs are inverted. Whole-vehicle wholesaling (42311) is ~72% of the group's revenue but only ~32% of its employment; new-parts wholesaling (42312) is the reverse — ~20% of revenue but ~51% of the jobs. Reselling a $30,000 car generates enormous top-line per worker (~$5.6M/employee); picking and delivering brake pads and filters is labor-intensive (~$1.0M/employee), and dismantling cars for parts is more labor-intensive still (~$0.39M/employee). The value added per dollar of sales runs opposite to the headline receipts. [2][3]

2. Margin runs opposite to size, in a clean ladder. This is the sharpest new evidence in the revised children, and it lines up perfectly with how finely each child breaks up what it buys: whole vehicles resold intact earn a 20.0% Census gross margin, tires 24.3%, new parts 35.0%, and used parts — where one purchased car is sold as dozens of separate pieces — 48.1%. The biggest child by revenue is the thinnest by margin; the smallest is the fattest. After Census-defined operating expenses the ladder compresses hard (42311 to 12.6% of total sales, 42313 to 13.7%, 42314 to 24.1%), which is the real reminder that gross margin here is a spread, not a profit. [5]

3. Concentration runs opposite to size too. The biggest child by revenue (42311) is fairly concentrated at the top (CR4 51%), and so is the smallest (42314, CR4 50%, highest HHI at 861) — while the second-biggest (42312, new parts) is the most fragmented in the whole group (CR4 17%, HHI 137). Size and concentration are unrelated here. [2][3]

4. Growth direction diverges. Used/recycled parts (42314) is the smallest slice but the fastest grower and a consolidation story; tires (42313) is a larger, slower slice under pressure from manufacturers pulling distribution in-house; whole vehicles (42311) is riding a cyclical supply rebound plus a structural shift online. One group, four different clocks. [8][9][18][22]

A large share of this revenue is not independent wholesaling. The Census Annual Integrated Economic Survey (AIES) for 2023 splits sales by type of operator, and the revised children now lead with it. In whole vehicles, 2023 sales were $838.5 billion — of which $464.8 billion came from manufacturers' sales branches and only $373.8 billion from merchant wholesalers proper. In new parts, 2023 sales were $223.6 billion, split $154.3 billion independent merchant wholesalers and $69.3 billion manufacturer-owned sales branches and offices. The tire equivalent was suppressed, and used parts has no comparable split. [4] These are not additive across children and should not be summed; the point is directional and it is important. More than half of the group's largest child, by its own newest federal figure, is captive manufacturer distribution — so the contestable independent pool is materially smaller than $1.07 trillion, and any market-sizing done off the headline will overstate the opportunity.

3. Size (this level's rollup figures)

These are Histometrics' ingested ground-truth federal statistics for NAICS 4231 specifically [2]:

The four children's establishment and employment figures sum exactly to these group totals (22,883 and 426,643), and their 2022 Economic Census receipts sum to within a rounding whisker (~$1,072.3B) — confirming a clean four-way partition on that vintage. Two caveats now attach. Firm counts do not add up: the children sum to ~14,227 vs. the group's 13,976, because a single firm operating in more than one of the four industries is counted once at the group level but can appear in multiple children. And payroll no longer reconciles child by child, because the 42312 primer now reports payroll on the AIES 2023 basis ($14.3 billion) rather than County Business Patterns, while the group's $31.19 billion remains a CBP 2023 figure — a source mismatch, not a data discrepancy. [2][3][4]

Two group-level signatures: revenue per employee is ~$2.5 million — the hallmark of pass-through distribution, where top line is huge but headcount and margin per dollar are small — and the group HHI (454.1) is lower than three of its four children's HHIs (755.8, 612, and 861). That is not a paradox: combining industries dilutes concentration because the giant in salvage auctions is not the giant in new parts or tires. No single company dominates the whole group, even though several dominate their own corner. [2][3]

Undercount caveat — read the trillion as a floor, and as a mixed measure. Federal statistics classify each establishment by its primary activity and route large chunks of real vehicle-wholesaling economics into other codes, so 4231 misstates the true footprint in several ways: (1) the biggest whole-vehicle names — Manheim, Copart, IAA (Insurance Auto Auctions) — mostly sell on consignment for a fee and are classified as agents/brokers (425120), not here [1]; (2) the mega parts chains (AutoZone, O'Reilly, Advance) are counted as retailers (441330) despite huge professional-wholesale arms [15][16]; (3) manufacturer-owned distribution straddles the boundary — sales branches located away from the plant are counted inside 42311 and 42312 (and are more than half of 42311's 2023 sales), while plant-attached distribution can land under manufacturing, and the tire figure that would have included branches was suppressed [4]; and (4) curbstoning and thousands of small, family-owned or non-employer recyclers and independents never fully surface in employer statistics [22][25]. Small and individual ownership dominates the long tail across all four children, so treat firm and employment counts as conservative. Broader trade estimates measure wider boxes and land higher: the light-vehicle aftermarket alone was about $435 billion in 2025, forecast to pass $500 billion by 2028 [15]; the whole auto-recycling value chain is put near $32 billion across 9,000-plus locations and 140,000-plus employees [22]; and one industry-research estimate puts tire wholesaling near $82 billion for 2024, against the $56–76 billion the federal tabulations capture [21].

4. Investable universe (where value concentrates across the children)

The group's trillion dollars of revenue does not translate into a broad menu of public stocks — and in 2025 the menu got shorter. Value concentrates in a handful of names, mostly in the whole-vehicle and parts children, and the single largest whole-car operator is private. Where the listed exposure actually sits:

• Whole vehicles (42311) — the deepest public bench, but skewed to marketplaces, not classic wholesalers. The cleanest listed plays are auction and digital-marketplace operators rather than title-taking buy/resell firms: the salvage duopoly — Copart (Nasdaq: CPRT), ~$4.6 billion of FY2025 revenue across 200-plus locations [10], and RB Global (NYSE: RBA), owner of IAA, which processes more than 2.5 million vehicles a year [11] — plus digital dealer-to-dealer wholesale (OPENLANE, NYSE: KAR, ~$1.93 billion of 2025 revenue on ~$28.8 billion of gross merchandise value; ACV Auctions, Nasdaq: ACVA, ~$760 million on ~$10.4 billion of GMV) and Carvana (NYSE: CVNA), whose ADESA wholesale arm sits beside its retail business [12]. The dominant whole-car operator, Manheim — 81 physical auction locations, more than 3.9 million vehicles inspected annually, more than 80,000 active dealers — is not directly investable, sitting inside Cox Automotive, a unit of privately held Cox Enterprises (~$23 billion of revenue). [8]
• New parts (42312) — one clean listed wholesaler plus adjacencies. Genuine Parts Company (NYSE: GPC, owner of NAPA) is the purest listed pure-distribution play — about $24 billion of total 2025 revenue, of which the North American Automotive segment is roughly $9.5 billion, with a plan to separate NAPA from its Motion industrial arm targeted for the first quarter of 2027 [13]. LKQ (Nasdaq: LKQ) adds collision, recycled, and European parts [14]; and the retail chains O'Reilly (ORLY, ~$71 billion market value), AutoZone (AZO, ~$50 billion), and Advance Auto Parts (AAP, ~$3.4 billion) run large professional-wholesale operations despite their retail classification — roughly half of O'Reilly's sales are to professional customers, and domestic commercial was 31.7% of AutoZone's domestic revenue in FY2025. [16]
• Used parts (42314) — one diversified distributor, and a listed set that shrank in 2025. LKQ is again the primary listed touchpoint (a diversified aftermarket-and-recycled distributor, not a pure salvage-parts play), with a North America segment running roughly $5.65 billion of revenue and $814 million of segment EBITDA in 2025 [14]. Two exposures left U.S. public markets last year: LKQ sold its self-service segment in September 2025 to an affiliate of Pacific Avenue Capital Partners at a stated $410 million enterprise value [14], and Radius Recycling — parent of the Pick-n-Pull chain — ceased to be a standalone U.S. public company when Toyota Tsusho acquired it in July 2025 [23]. Copart and RB Global remain the asset-light, fee-based way to touch the salvage-auction layer that feeds the recyclers. [10][11]
• Tires (42313) — no U.S. pure-play at all. The leaders are private: lender-owned American Tire Distributors (110-plus distribution centers; sales peaked near $5 billion in 2019 before two bankruptcies) [18]; family-owned U.S. AutoForce (~$978 million of revenue, 68 distribution centers); Bain Capital-backed Dealer Tire; and two manufacturer joint ventures — NTW/TBC (Michelin/Sumitomo, 100-plus distribution centers) and TireHub (Goodyear/Bridgestone, 80-plus locations at launch) [19]. Public investors reach tire distribution only indirectly, through the listed tiremakers that co-own the JVs (Goodyear, Nasdaq: GT; Bridgestone, Tokyo: 5108; Michelin, Euronext Paris: ML; Sumitomo, Tokyo: 8053) [19] — and that route carries its own warning: Goodyear's share of TireHub's net loss was $41 million in 2025 and $35 million in 2024, evidence that manufacturer-backed national scale does not guarantee attractive distribution economics. [20]

A comparability warning that applies group-wide. The scale figures above are not like-for-like and must not be assembled into a market-share table. Copart's and Carvana's numbers mix principal and agent activity; OPENLANE and ACV report fees on consigned vehicles but full selling price where they own the vehicle; GMV counts dollars transacted that never enter revenue at all; and Census sales are yet a third measure. [12] The same trap sits between the children: LKQ's North America segment spans several of these codes and should not be valued as if all of it were used parts. [14]

Beneath all four sits a long tail of thousands of privately held independents — the majority of firms and a large share of the real economic activity — which is where private capital actually participates. There is no dedicated sector exchange-traded fund (ETF) for vehicle wholesaling. Company-by-company scale, tickers, and revenue splits are in each child primer.

5. How the money works

Across all four children this is distribution, not manufacturing — so it earns a spread on volume, and the economics of a regulated utility (rate base), a REIT (funds from operations), or a miner (all-in sustaining cost) do not apply. But the group splits into two distinct profit models:

• Title-taking wholesalers (principals) — most whole-vehicle, new-parts, tire, and used-parts firms — buy inventory and earn the gross spread per unit (sell price minus acquisition, transport, reconditioning, warehousing, and floorplan interest) times volume. The Census margin ladder in Section 2 is the spread before any of that cost: 20.0% in whole vehicles, 24.3% in tires, 35.0% in new parts, 48.1% in used parts, compressing to 12.6%, 13.7%, and 24.1% respectively after Census-defined operating expenses [5]. Concrete anchors: Carvana earned about $996 of gross profit per wholesale unit in 2024 on cars worth many multiples of that [12], and tire distributors carried $9.2 billion of year-end inventory against $56.2 billion of own-account sales [5]. The winning levers are inventory turnover, fill rate, delivery/route density, vendor rebates, buy discipline, and cash conversion. Because the model is working-capital-heavy, leverage is the killer: American Tire Distributors met shrinking volume with roughly $1.9 billion of debt against ~$30 million of cash and ended in bankruptcy. Money is made "on the buy." [18]
• Marketplace / auction operators (agents) — the salvage duopoly and the digital whole-car platforms — don't own the cars. They charge buyer and seller fees plus ancillary services (transport, inspection, titling, financing, data) and live on units, gross merchandise value (GMV — total dollar value transacted), and take-rate. OPENLANE converted ~$28.8 billion of 2025 GMV into ~$1.93 billion of revenue — $833.5 million of auction and related fees, $257.1 million of SaaS and other, $410.2 million of purchased-vehicle sales, and $433.7 million of finance revenue — while ACV produced ~$760 million on ~$10.4 billion of GMV. Ancillary attach, not the core auction fee, is the profit-growth story. [12] Salvage auctions are the high-margin extreme: they sell total-loss vehicles for insurers almost entirely on consignment, carrying near-zero inventory risk, backed by sticky multi-year insurer contracts. [10][11] This is why the most attractive listed economics in the whole group sit in the agent layer, not the principal layer.

In used parts specifically, the unit of economics is the vehicle: one salvage car is monetized in layers — sellable parts (the profit engine, and the reason for that 48.1% gross margin), rebuildable cores, catalytic-converter precious metals, and scrap metal as a commodity floor. Those last two layers swing hard and independently: in 2025 LKQ's average rhodium, platinum, and palladium prices rose 40%, 38%, and 20% while its average scrap price fell 9%. [14] Vehicle-acquisition cost is the biggest single swing factor, and most wholesale recycled inventory is bought at third-party auction without long-term contracts. [14]

One accounting caution that runs through every child: the Census "gross margin" and "gross profit" measures above are survey definitions, not GAAP, and they cannot be applied to agent marketplaces at all, since the vehicle's value never enters their revenue. [5][12]

6. Demand drivers

Wholesale demand across 4231 is derived — it depends on the size, age, use, and turnover of the U.S. vehicle fleet — and the drivers rhyme across the children:

• A large, aging, heavily driven fleet — about 289 million light vehicles in operation in 2025, up 3 million year over year, at a record average age of 12.8 years, with vehicles in the 6-to-14-year aftermarket "sweet spot" expected to make up roughly 70% of the fleet for years [6][15]; 297.5 million registered motor vehicles covered 3.294 trillion miles in 2024, up from 3.247 trillion in 2023 [7]. Older cars out of warranty are a structural tailwind for parts, tires, and recycled components.
• Fleet turnover and off-lease supply — new-vehicle sales (~16 million units), used-vehicle demand (~20 million units), and lease maturities (down to ~2.4 million in 2025 from ~4 million in 2020, projected to rebound toward ~3 million in 2026) drive whole-vehicle wholesale volume and pricing. The Manheim Used Vehicle Value Index ended 2025 up just 0.4% year over year, well below its long-run ~2.3% pace, reflecting affordability strain and tariff-driven volatility. [8][9]
• Repair & total-loss activity — rising repair costs and expensive sensors/ADAS (advanced driver-assistance systems) push more crashes into total-loss, feeding salvage and recycled-parts supply. CCC reported that more than 70% of 2024 total-loss valuations involved vehicles at least seven years old, and LKQ has cited alternative-parts utilization near a record ~40% in early 2026 — insurer acceptance is the swing variable for used-parts demand. [24]
• Wear items and replacement cycles — replacement tires vastly outnumber original-equipment fitments: of roughly 337 million U.S. tire shipments in 2024 (about 340 million forecast for 2025), the large majority are replacement, with 2025 projections of 221.6 million replacement passenger, 37.8 million light-truck, and 25.2 million medium-truck tires. Parts and tires are non-discretionary wear items, giving the group a defensive quality. [21]
• Interest rates, credit, and commodity prices — floorplan carry and buyer affordability swing volumes; scrap-steel and precious-metal prices set a floor and a swing factor on recycler economics. [8][14]

7. Regulation

Vehicle wholesaling is lightly regulated relative to its size — no price or rate regulation, no entry cap — with oversight concentrated at the state level plus a few federal rules, varying by child:

• Licensing & titling (mainly 42311/42314): state dealer/wholesaler licensing with surety bonds and a physical location, with unlicensed curbstoning actively enforced; odometer and salvage/branded-title law, including NHTSA's requirement of odometer disclosure at transfer for the first 20 years on model-year 2011 and newer vehicles; the Federal Trade Commission's Used Car Rule (Buyers Guide); and IRS/FinCEN Form 8300 cash-reporting over $10,000. [25] For recyclers, add NMVTIS (National Motor Vehicle Title Information System) reporting of acquired junk or salvage vehicles and their disposition, catalytic-converter theft rules, and EPA fluid and refrigerant handling — used oil under 40 CFR Part 279, universal-waste rules for batteries, a venting prohibition and approved recovery equipment for automotive refrigerants, and added RCRA storage and transport duties above 100 kilograms of hazardous waste per month. [28]
• Right to Repair, trade & emissions (mainly 42312): the federal REPAIR Act (H.R. 1566, which would guarantee independent shops access to vehicle repair and diagnostic data); Section 232 tariffs under Proclamation 10908 — an additional 25% on specified imported vehicles and key parts, effective for parts no later than May 3, 2025, with qualifying USMCA (U.S.-Mexico-Canada Agreement) parts exempt pending a process to tariff their non-U.S. content; and Clean Air Act enforcement against aftermarket defeat devices, which produced 172 civil cases and $55.5 million in penalties from FY2020 through FY2023, including a $7.4 million penalty against distributor Meyer Distributing in 2025. [26]
• Import duties & recall traceability (mainly 42313): antidumping/countervailing duty orders move cost of goods directly — the China passenger and light-truck tire orders were retained after a 2026 sunset review, orders on Korea, Taiwan, Thailand, and Vietnam have run since July 2021, and a truck-and-bus-tire order on Thailand landed in December 2024 — alongside TREAD/FAST Act tire-registration obligations for independent sellers and recordkeeping under 49 CFR Part 574. [27]
• Recycled-parts disclosure (42314): non-OEM (original equipment manufacturer) crash-parts laws in at least 35 states, roughly 31 requiring written disclosure and about a quarter requiring the customer's explicit consent, with occasional state bills (recent New York and Texas proposals among them) that would mandate OEM parts on newer vehicles. Environmental and zoning rules bind land-intensive yards, and the work is physically hazardous — BLS recorded seven fatal occupational injuries in NAICS 42314 in 2023. [28]

The through-line is licensing, titling integrity, consumer disclosure, and trade policy — not price or entry control. Tariffs and Right-to-Repair are the live federal wildcards for the group, and emissions-compliance enforcement has become a distributor-level exposure, not just a manufacturer's problem. [26]

8. Consolidation

The group is best read as consolidated tops over fragmented bottoms, with a different consolidation engine in each child:

• Whole vehicles (42311): salvage is a duopoly — Copart (~50% share) and RB Global's IAA (~35%) — after RB Global's 2023 acquisition of IAA, though the shares move: insurers such as Progressive have shifted salvage volume between the two [11]. The whole-car side is led by private Manheim, with Carvana's 2022 purchase of ADESA's U.S. physical auctions and digital-first entrants (ACV, OPENLANE) reshaping the field, and incumbents responding by digitizing [8][12]. The whole layer also faces bypass risk — direct dealer-to-dealer trades, OEM and captive closed networks, fleet private sales, and dismantlers buying straight from insurers. [10]
• New parts (42312): low official concentration (HHI 137) but active consolidation — national chains and PE-backed distributors buying independents, with scale at the top meaning network density: Genuine Parts ran 76 distribution centers, 2,471 company-owned stores, and 4,317 independently owned stores in North America at year-end 2025 [13]. The marquee live event is GPC's plan to separate NAPA from Motion by the first quarter of 2027, and O'Reilly's reported ~$10 billion bid for the NAPA automotive division (reported, not completed) [13]. Heavy-duty truck parts consolidate separately — the merged FleetPride/TruckPro now spans 450-plus locations under American Securities and Platinum Equity [17].
• Tires (42313): the defining trend is vertical integration by the manufacturers — Goodyear/Bridgestone (TireHub) and Michelin/Sumitomo (NTW/TBC) pulling wholesale in-house since 2018, squeezing the largest independent into an October 2024 Chapter 11 filing (ATD's second in six years) and a March 2025 sale of substantially all assets to its lenders [18][19]. Firm-level concentration remains moderate (CR4 43.3%, HHI ~612) [3], and Modern Tire Dealer puts independents at 80% of the U.S. consumer-tire wholesale channel in 2025 — a channel estimate, not a Census ratio, and "independent" does not mean small [19]. Downstream retail is consolidating too, with Walmart leading U.S. tire unit share (~15%) and Discount Tire leading dollar share (~16%) in early 2025, squeezing the wholesale layer from the other side. [19]
• Used parts (42314): fragmented but consolidating behind LKQ (built through hundreds of acquisitions) and PE-backed roll-ups such as Fenix Parts (a former public roll-up, now owned by Stellex Capital, with more than 34 locations) buying independents as owners retire [23]. The 2025 transactions point the same direction but change who owns the assets rather than how many owners there are: LKQ's self-service divestiture and Toyota Tsusho's purchase of Radius Recycling both moved operating exposure out of U.S. public markets. [14][23]

Barriers are high for the leaders (land, storage, transport networks, long-term insurer/fleet contracts, data platforms) and low for the tail (a license, a bond, and a floorplan line) — which is why the fragmented bottom persists beneath every consolidated top.

9. Risks

The group's risks cluster into a few shared themes, weighted differently per child:

• Cyclicality & price risk (heaviest in 42311/42313): title-takers hold depreciating, debt-financed inventory; a drop in used-vehicle or tire values can turn thin spreads negative. The Manheim index's 0.4% gain in 2025 shows how flat values can get even without a downturn, and off-lease supply whipsaws whole-vehicle volumes. [8][9]
• Leverage (heaviest in 42313): a thin-margin, working-capital-heavy model punishes debt in a downturn — ATD is the cautionary tale [18] — and scale alone is no cure, as Goodyear's $41 million share of TireHub's 2025 net loss shows [20].
• Disintermediation (heaviest in 42313, rising in 42312 and 42311): manufacturers routing volume through their own JVs; automaker data control and e-commerce squeezing the middleman; direct-to-dealer channels reducing the independent distributor to low-margin fulfillment. [10][18][26]
• Tariffs & trade policy (heaviest in 42312/42313): Section 232 and tire antidumping duties raise cost of goods and inject volatility, and pass-through is usually possible but incomplete. Goodyear reported that higher raw-material costs cut its 2025 segment operating income by $443 million and forecast roughly $300 million of annualized tariff cost for 2026 (company figures, not industry totals). [20][26][27]
• Supplier concentration & credit risk (newly visible, heaviest in 42312): roughly 55% of Genuine Parts' 2025 U.S. automotive inventory purchases came from just ten suppliers, and GPC booked a $151 million expected-credit-loss reserve tied to supplier First Brands' 2025 bankruptcy — a reminder that a distributor's balance sheet is exposed upstream as well as downstream. [13]
• The EV (electric-vehicle) transition (heaviest in 42312/42314, watch item in 42311): battery-electric vehicles need fewer wear parts, see reduced brake wear from regenerative braking, and lack engines, transmissions, and catalytic converters — the first two of which are among LKQ's largest North American SKUs. Partial offsets exist in collision parts, ADAS modules, and battery recycling: CCC found EVs averaged 22 replaced parts per repair in 2024 versus 16 for internal-combustion vehicles, which is evidence of collision complexity, not a guarantee of recycled-parts demand. Residuals are the near-term problem — off-lease EVs are projected to more than triple in 2026 versus 2025, with battery health and repairability making values hard to underwrite. [9][14][24][26]
• Concentration & contract risk (42311/42314): the recycled-parts chain depends on a two-platform salvage supply (Copart, IAA) and on long-term insurer contracts that can shift. [11][14]
• Regulatory reversal (42314): state pushes to mandate OEM parts on newer vehicles would cap recycled-parts demand. [28]
• Environmental, safety, and labor exposure (heaviest in 42313/42314): contamination, zoning, and cleanup costs on land-intensive yards are ever-present, and reported EBITDA can overstate distributable cash where remediation or fluid- and battery-handling capex has been deferred; the work is hazardous [28]; and driver availability, wage inflation, and vehicle-insurance costs press on every child's delivery model.

10. How to invest & outlook

Public routes are narrower than the group's size implies and concentrate in the agent/marketplace layer and one clean parts wholesaler:

• Highest-quality, most defensible: the salvage duopoly (Copart, RB Global) — asset-light, fee-based, near-zero inventory risk, and able to prosper on volume even when higher auction prices squeeze the dismantlers downstream. [10][11]
• Growth & take-rate: digital whole-car marketplaces (OPENLANE, ACV Auctions) and blended retail-plus-wholesale (Carvana, whose equity is driven mainly by retail). [12]
• Direct distribution & income: Genuine Parts (GPC), a dividend stalwart with 69 consecutive annual increases and a ~2.8% yield, with the NAPA/Motion separation a potential catalyst [13], plus the liquid retail chains (ORLY, AZO, AAP), whose combined market value rose about 42% from 2015 to 2025 [16], and diversified LKQ [14].
• Used parts: a thinner bench than a year ago — LKQ remains the primary listed touchpoint, but the self-service divestiture and the Radius/Toyota Tsusho deal removed two exposures from U.S. public markets in 2025. [14][23]
• Tires: indirect only, via the listed tiremakers (GT, 5108, ML, 8053) — with TireHub's losses a live reminder that owning the JV is not the same as owning a good business. [19][20] There is no pure-play public buy-and-resell wholesaler in any of the four children and no dedicated sector ETF.

Private routes are where most capital actually participates, because the group is fundamentally a private-market business: backing or rolling up independent wholesalers, remarketers, regional auctions, tire distributors, and auto recyclers; platform buy-and-build (the FleetPride/TruckPro heavy-duty roll-up and the Worldpac carve-out to Carlyle are the marquee cases) [17]; buying groups and co-ops that pool purchasing for thousands of independents [17]; distressed-control and private-credit ownership (ATD's restructuring passed control to a lender consortium) [18]; sponsor-owned platforms such as Dealer Tire and Fenix Parts [19][23]; the real-estate angle on land-intensive yards; and wholesale fintech, software, and data layers (Car-Part.com, inspection and condition data, title processing, transport brokerage, floorplan lending). [22][23] Diligence in the piece-out businesses should center on gross profit per donor vehicle, parts sold per donor, acquisition cost by source, inventory age and turns, fill rate, auction dependence, title compliance, and normalized environmental capex.

Outlook (judgment, not fact). The 2026 setup is broadly constructive but uneven across the four clocks: whole-vehicle wholesaling faces a supply rebound (lease maturities up roughly 27% toward ~3 million units, Manheim index forecast up about 2%) that loosens supply and normalizes prices [8][9]; new parts ride a record-old, growing fleet as a durable, defensive tailwind, with the aftermarket forecast to pass $500 billion by 2028 [6][15]; recycled parts are the fastest structural grower, with independent forecasts of ~8% annual growth from about $17.4 billion in 2024 toward ~$30 billion by 2033 [22]; and tires remain a stable-demand but disintermediation-pressured slice where the pie grows slowly and the question is who carries the slices [21]. The clearest cross-group tailwind is the continued shift of wholesale online and toward data and fee models [12]; the clearest shared wildcards are tariff-driven cost volatility and the EV transition [9][26][27].

Analytical caution. The most common error at this level is to treat the trillion-dollar headline as a trillion-dollar addressable market of independent middlemen. It is not: more than half of the largest child's newest reported sales are manufacturers' own sales branches [4], the biggest consignment operators are classified outside the group entirely [1], the mega parts chains are counted as retailers [16], and the tire line has two unreconciled federal figures [3][5]. No single margin, concentration ratio, or share table captures 4231 cleanly. On balance, its durable economics — non-discretionary, fleet-driven throughput on an aging fleet — are most cleanly captured by the fee-based auction leaders and the one listed parts wholesaler for public investors, and by consolidation of the fragmented private tail for everyone else. These are projections, not certainties. For full company detail and section-by-section depth, see the four child primers (42311, 42312, 42313, 42314).

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Sources

This is a four-child rollup. The size and concentration figures for NAICS 4231 in Sections 2–3 are Histometrics' ingested ground-truth federal statistics; the remaining sources are drawn from the revised child primers for 42311, 42312, 42313, and 42314.

1. U.S. Census Bureau — 2022 NAICS definitions, subsector 42 and industry group 4231 and its children (scope and exclusions vs. retail subsector 441, agents/brokers 425120, scrap dismantling 423930, and manufacturing). https://www.census.gov/naics/?details=42&input=42&year=2022; https://www.census.gov/naics/?details=423110&input=423110&year=2022
2. U.S. Census Bureau — County Business Patterns 2023 (establishments, employment, annual and first-quarter payroll) and 2022 Economic Census / Concentration (receipts, firm count, CR4/CR8/CR20/CR50, HHI). Histometrics ingested ground-truth federal statistics for NAICS 4231. https://www.census.gov/programs-surveys/cbp.html; https://www.census.gov/programs-surveys/economic-census.html
3. U.S. Census Bureau — child-level federal statistics: County Business Patterns 2023 and 2022 Economic Census concentration/receipts for NAICS 423110, 423120, 423130, and 423140; U.S. Small Business Administration — Table of Size Standards 2023 (250 / 200 / 200 / 125 employees respectively). The 42313 receipts and concentration figures are Histometrics ingested statistics carried without a public URL, per that child primer. https://data.census.gov/profile/423120_-_Motor_Vehicle_Supplies_and_New_Parts_Merchant_Wholesalers?codeset=naics~423120; https://data.census.gov/profile/423130_-_Tire_and_Tube_Merchant_Wholesalers?codeset=naics~423130; https://data.census.gov/profile/423140_-_Motor_vehicle_parts_%28used%29_merchant_wholesalers?codeset=naics~423140; https://www.sba.gov/document/support-table-size-standards
4. U.S. Census Bureau — Annual Integrated Economic Survey (AIES), 2023 sales by type of operation for NAICS 423110 ($838.5B total; $373.8B merchant wholesalers, $464.8B manufacturers' sales branches) and 423120 ($223.6B total; $154.3B merchant wholesalers, $69.3B manufacturers' branches; $14.3B payroll); 423130 all-operating-types total suppressed. 2024. https://data.census.gov/table?tid=AIESBASICTIMESERIES.AIES42BASIC; https://data.census.gov/table/AIESBASICTIMESERIES.AIES42BASIC?codeset=naics~423130&g=010XX00US
5. U.S. Census Bureau — 2022 Economic Census, Gross Margin and Gross Profit table (EC2242GRMARGPROF) for NAICS 423110 (20.0% gross margin, 12.6% gross profit), 423120 (35.0% merchandise gross margin, independent merchant wholesalers), 423130 ($56.2B sales, 24.3% gross margin, 13.7% gross profit, $9.2B inventory), and 423140 (48.1% gross margin, 24.1% gross profit). 2024. https://data.census.gov/table/ECNGRMARGPROF2022.EC2242GRMARGPROF
6. S&P Global Mobility — "U.S. Vehicle Age Rises Again to 12.8 Years in 2025" (289 million light vehicles in operation, up 3 million year over year; record average age). 2025. https://press.spglobal.com/2025-05-21-U-S-Vehicle-Age-Rises-Again-to-12-8-Years-in-2025%2C-According-to-S-P-Global-Mobility
7. U.S. Federal Highway Administration — Traffic Volume Trends, Table VM-1 (3.294 trillion vehicle-miles traveled in 2024, up from 3.247 trillion in 2023; 297.5 million registered motor vehicles). 2024. https://www.fhwa.dot.gov/policyinformation/statistics/2024/pdf/vm1.pdf; https://www.fhwa.dot.gov/policyinformation/statistics/2024/vm1.cfm
8. Cox Automotive — Manheim Used Vehicle Value Index, Q4 2025 report and 2026 outlook (index +0.4% in 2025 vs. ~2.3% long-run pace; ~2% forecast for 2026); Manheim company overview (81 auction locations, 3.9M+ vehicles inspected annually, 80,000+ active dealers); Cox Enterprises scale (~$23B revenue). 2025–2026. https://www.coxautoinc.com/insights/q4-2025-muvvi/; https://www.coxautoinc.com/brands/manheim/
9. Edmunds — "Used Car Prices Approach Records… Off-Lease Inventory" (Q1 2026 Insights); Cox Automotive off-lease and lease-maturity forecasts (~2.4M maturities in 2025 from ~4M in 2020, rebounding toward ~3M in 2026; off-lease EVs projected to more than triple in 2026); new-vehicle SAAR ~16M and used-vehicle demand ~20M. 2025–2026. https://www.edmunds.com/car-news/q1-2026-edmunds-insights-used-car-report.html
10. Copart, Inc. — Form 10-K for fiscal year 2025 (~$4.6B revenue; 200+ locations; consignment model and bypass risk). 2025. https://www.sec.gov/Archives/edgar/data/900075/000162828025042946/cprt-20250731.htm
11. RB Global, Inc. — full-year 2024 results and Form 10-K for fiscal year 2025 (IAA vehicle-volume profile, 2.5M+ vehicles a year); Transportation Today, "RB Global rebuild takes hold as shifting Progressive behavior puts new pressure on Copart" (salvage market shares, Copart ~50% / IAA ~35%). 2025–2026. https://www.businesswire.com/news/home/20250218757724/en/RB-Global-reports-fourth-quarter-and-full-year-2024-results; https://www.sec.gov/Archives/edgar/data/1046102/000162828026011682/rba-20251231.htm; https://transportationtodaynews.com/news/36872-rb-global-rebuild-takes-hold-as-shifting-progressive-behavior-puts-new-pressure-on-copart/
12. OPENLANE, Inc. — Form 10-K FY2025 (~$1.93B revenue on ~$28.8B GMV, ~1.5M vehicles; revenue components); ACV Auctions Inc. — Form 10-K FY2025 (~$760M revenue, 829,000 vehicles, ~$10.4B GMV; seasonality); Carvana Co. — Form 10-K FY2024 (199,780 wholesale units, 955,802 ADESA marketplace units, $346M wholesale gross profit, ~$996 gross profit per wholesale unit); National Auto Auction Association — AuctionNet USA (8M+ wholesale used vehicles sold by member auctions in 2025, 820,000 digital-only); Research and Markets, "US Vehicle Auction Market Trends 2025-2030" (~$3.47B of 2024 service revenue). 2024–2026. https://www.sec.gov/Archives/edgar/data/1395942/000139594226000006/opln-20251231.htm; https://www.sec.gov/Archives/edgar/data/1637873/000163787326000011/acva-20251231.htm; https://www.sec.gov/Archives/edgar/data/1690820/000169082025000074/cvna-20241231.htm; https://naaa.com/auctionnetusa/; https://www.globenewswire.com/news-release/2025/08/07/3129425/28124/en/US-Vehicle-Auction-Market-Trends-2025-2030.html
13. Genuine Parts Company — Form 10-K FY2025 (~$24B total revenue; NA Automotive $9.520B revenue, 38.8% gross margin, 7.1% EBITDA margin; 76 distribution centers, 2,471 company-owned and 4,317 independently owned stores; NAPA/Motion separation targeted Q1 2027; ~55% of U.S. automotive inventory purchases from ten suppliers; $151M First Brands credit-loss reserve); dividend declarations (69 consecutive annual increases, ~2.8% yield); Modern Distribution Management / Transport Topics on O'Reilly's reported ~$10B bid for the NAPA automotive unit (reported, not completed). 2025–2026. https://www.sec.gov/Archives/edgar/data/40987/000004098726000003/gpc-20251231.htm; https://www.prnewswire.com/news-releases/genuine-parts-company-declares-regular-quarterly-dividend-302617542.html; https://www.mdm.com/news/top-distributor-sectors/automotive/report-oreilly-submits-10b-bid-for-genuine-parts-automotive-unit/; https://www.ttnews.com/articles/genuine-parts-oreilly-bid
14. LKQ Corporation — Form 10-K FY2025 (North America segment $5.651B revenue, $814M segment EBITDA, 42.8% gross margin, 14.4% EBITDA margin; self-service segment sale to a Pacific Avenue Capital Partners affiliate at $410M enterprise value; rhodium/platinum/palladium prices +40%/+38%/+20% and scrap −9% in 2025; engines and transmissions as major SKUs; auction-sourced inventory and bidding competition; tariff and supplier exposure). 2026. https://www.sec.gov/Archives/edgar/data/1065696/000106569626000012/lkq-20251231.htm
15. Auto Care Association — "U.S. Light Vehicle Automotive Aftermarket Projected to Reach $435 Billion in 2025" (forecast to pass $500B by 2028; 6-to-14-year fleet "sweet spot"). 2025. https://www.autocare.org/news/latest-news/details/2025/06/12/u.s.-light-vehicle-automotive-aftermarket-projected-to-reach-$435-billion-in-2025
16. O'Reilly Automotive — Form 10-K FY2025 (~50% professional/DIFM sales); AutoZone — Form 10-K FY2025 (domestic commercial 31.7% of domestic sales); market-capitalization data for GPC, ORLY, AZO, AAP and AAPEX, "Market Capitalization of the Big 4 Auto Parts Retailers" (combined value up ~42% 2015–2025). 2025–2026. https://www.sec.gov/Archives/edgar/data/898173/000089817326000009/orly-20251231x10k.htm; https://www.sec.gov/Archives/edgar/data/866787/000110465925102611/azo-20250830x10k.htm; https://stockanalysis.com/; https://www.aapexshow.com/blog/market-capitalization-auto-parts-retailers/
17. Modern Distribution Management — "FleetPride, TruckPro Merge to Form Largest Independent Heavy-Duty Aftermarket Distributor" (450+ locations; American Securities / Platinum Equity ownership); Advance Auto Parts Form 8-K, Worldpac sale to Carlyle for $1.5B; The Pronto Network / Automotive Parts Services Group and the Aftermarket Auto Parts Alliance (buying-group structure). 2024–2025. https://www.mdm.com/news/top-distributor-sectors/automotive/fleetpride-truckpro-merge-to-form-largest-independent-heavy-duty-aftermarket-distributor/; https://www.sec.gov/Archives/edgar/data/1158449/000119312524205390/d858165d8k.htm; https://theprontonetwork.com/home/about; https://www.thegroupapsg.com/
18. American Tire Distributors — Modern Tire Dealer, "ATD Files for Chapter 11 Reorganization" (October 2024, second filing in six years; ~$1.9B debt against ~$30M cash); PR Newswire, "American Tire Distributors Completes Sale Transaction With Lender Group" (March 2025) and "A New Company With Committed Owners…"; company network description and revenue history (110+ distribution centers; sales peaked near $5B in 2019). 2024–2025. https://www.moderntiredealer.com/industry-news/wholesale-distribution/article/55237518/atd-files-for-chapter-11-reorganization; https://finance.yahoo.com/news/american-tire-distributors-completes-sale-130500138.html; https://www.prnewswire.com/news-releases/american-tire-distributors-a-new-company-with-committed-owners-experienced-leadership-team-and-strong-financial-position-302393107.html; https://www.atd.com/about-us/article/we-are-american-tire-distributors/index.html
19. Tire distribution structure and channel share — Modern Tire Dealer and TireHub, "Goodyear and Bridgestone Form Tire Distribution Network: TireHub" (2018; 80+ locations at launch); PR Newswire / Sumitomo and National Tire Wholesale, Michelin–Sumitomo NTW/TBC joint venture (2018; 100+ distribution centers, described at formation as the second-largest U.S. wholesale player); U.S. Venture, "U.S. AutoForce" profile (~$978M revenue, 68 distribution centers); Bain Capital investment in Dealer Tire (2018); Modern Tire Dealer, "MTD Facts Issue: Independents Dominate Wholesale Channel" (independents ~80% of the 2025 U.S. consumer-tire wholesale channel); Openbrand, "2025 U.S. Tire Market Share & Retail Sales Trends" (Walmart ~15% unit share, Discount Tire ~16% dollar share). 2018–2025. https://www.moderntiredealer.com/industry-news/consumer-tires/article/11532018/goodyear-and-bridgestone-form-tire-distribution-network-tirehub-2018-04-16; https://www.tirehub.com/about-us/; https://www.prnewswire.com/news-releases/michelin-and-sumitomo-corporation-to-create-second-largest-wholesale-player-in-the-us-and-mexico-300577127.html; https://ntw.com/About-Us/; https://www.usventure.com/businesses/us-autoforce/; https://www.baincapital.com/news/dealer-tire-announces-significant-investment-bain-capital-private-equity; https://www.moderntiredealer.com/industry-news/wholesale-distribution/article/55356491/mtd-facts-issue-independents-dominate-wholesale-channel; https://openbrand.com/newsroom/blog/tire-market-top-brands-retailers-market-share-retail-sales-data-trends
20. Goodyear Tire & Rubber Company — Form 10-K for fiscal year 2025 (share of TireHub net loss $41M in 2025 and $35M in 2024; raw-material costs reduced 2025 segment operating income by $443M; ~$300M annualized 2026 tariff cost). 2026. https://www.sec.gov/Archives/edgar/data/42582/000162828026006708/gt-20251231.htm
21. IBISWorld — "Tire Wholesaling in the US" (~$82B U.S. tire-wholesaling revenue estimate for 2024, broader scope than the Census code); U.S. Tire Manufacturers Association — 2025 U.S. Tire Shipment Forecast (~337 million shipments in 2024, ~340 million forecast for 2025; 221.6M replacement passenger, 37.8M light-truck, 25.2M medium-truck for 2025); Statista — U.S. replacement tire market (~$58B at retail, 2024). 2024–2025. https://www.ibisworld.com/united-states/market-research-reports/tire-wholesaling-industry/; https://www.ustires.org/newsroom/ustma-july-2025-forecast; https://www.statista.com/topics/3769/tire-market-in-the-us/
22. Automotive Recyclers Association — industry overview (~$32B value chain, 9,000+ locations, 140,000+ employees; recycled parts 20–80% cheaper than new); Auto Recycling World — "Recycled Auto Parts Market Forecast To Grow 8% A Year To 2033" (~$17.4B in 2024 to ~$30B by 2033). 2024–2025. https://www.a-r-a.org/; https://www.a-r-a.org/about-us/; https://autorecyclingworld.com/recycled-auto-parts-market-forecast-to-grow-8-a-year-to-2033/
23. Recycled-parts ownership shifts — Toyota Tsusho Corporation, announcement of the Radius Recycling acquisition (July 2025); Fenix Parts growth timeline (34+ locations) and GlobeNewswire, "Fenix Parts Stockholders Approve Merger Agreement with Stellex Capital Management LP." 2018–2025. https://www.toyota-tsusho.com/english/press/detail/250711_006639.html; https://fenixparts.com/growth-timeline/; https://www.globenewswire.com/news-release/2018/04/09/1467291/0/en/Fenix-Parts-Stockholders-Approve-Merger-Agreement-with-Stellex-Capital-Management-LP.html
24. CCC Intelligent Solutions — Crash Course Report (70%+ of 2024 total-loss valuations were vehicles seven years or older; EVs averaged 22 replaced parts per repair vs. 16 for internal-combustion vehicles); Autobody News — "LKQ Reports Q1 Revenue Growth…" (alternative-parts utilization near a record ~40%). 2024–2026. https://ir.cccis.com/news-releases/news-release-details/ccc-crash-course-report-highlights-forces-reshaping-us-vehicle; https://www.autobodynews.com/news/lkq-reports-q1-revenue-growth-as-ceo-cites-signs-of-recovery-in-north-america
25. Vehicle titling, licensing, and disclosure — U.S. Federal Trade Commission, Used Motor Vehicle Trade Regulation Rule (Buyers Guide); National Highway Traffic Safety Administration, consumer alert on odometer-disclosure changes (disclosure at transfer for the first 20 years on model-year 2011 and newer vehicles); Bumper / state motor-vehicle agencies on curbstoning, licensing, surety bonds, and salvage-title rules. 2014–2024. https://www.federalregister.gov/documents/2014/11/28/2014-28000/used-motor-vehicle-trade-regulation-rule; https://www.nhtsa.gov/press-releases/consumer-alert-changes-odometer-disclosure-requirements; https://www.bumper.com/car-advice/buying/curbstoning-scam
26. New-parts regulation — U.S. Congress, REPAIR Act (H.R. 1566, 119th Congress); Federal Register, Proclamation 10908 (additional 25% tariff on specified imported vehicles and key parts, effective for parts no later than May 3, 2025) and Congressional Research Service / Auto Care Association on Section 232 automotive tariffs and USMCA exemptions; U.S. Environmental Protection Agency, "Stopping Aftermarket Defeat Devices" (172 civil cases, $55.5M in penalties FY2020–FY2023) and the $7.4M Meyer Distributing penalty (2025). 2025–2026. https://www.congress.gov/bill/119th-congress/house-bill/1566/text; https://www.federalregister.gov/documents/full_text/html/2025/04/03/2025-05930.html; https://www.congress.gov/crs-product/IN12545; https://www.epa.gov/enforcement/national-enforcement-and-compliance-initiative-stopping-aftermarket-defeat-devices; https://www.epa.gov/newsreleases/indiana-auto-parts-distributor-pay-74m-selling-emissions-defeat-devices-cars-and
27. Tire trade and recall regulation — U.S. International Trade Commission, passenger vehicle and light truck tires from China, five-year sunset reviews (orders retained, 2026); Federal Register / Commerce, antidumping duty orders on passenger and light-truck tires from Korea, Taiwan, Thailand, and Vietnam (2021) and on truck and bus tires from Thailand (December 2024); Tire Business on import shifts to third countries; NHTSA, 49 CFR Part 574 (tire identification and recordkeeping) and SEMA on TREAD/FAST Act tire-registration requirements for independent sellers. 2015–2026. https://www.usitc.gov/press_room/news_release/2026/er0623_68791.htm; https://www.federalregister.gov/documents/2021/07/19/2021-15270/passenger-vehicle-and-light-truck-tires-from-the-republic-of-korea-taiwan-and-thailand-antidumping; https://www.federalregister.gov/documents/2024/12/17/2024-29606/truck-and-bus-tires-from-thailand-antidumping-duty-order; https://www.tirebusiness.com/news/us-consumer-demand-tires-grew-2024; https://www.ecfr.gov/current/title-49/subtitle-B/chapter-V/part-574; https://www.sema.org/news-media/enews/2015/50/new-law-requires-tire-registration-independent-sellers-and-revised-tpms
28. Used-parts regulation and safety — Matthiesen, Wickert & Lehrer and the Connecticut General Assembly OLR on state non-OEM/recycled crash-parts laws (35+ states regulate, ~31 require written disclosure, ~25% require consent; recent New York and Texas OEM-mandate bills); NMVTIS, "Data Required" (junk/salvage yard reporting); U.S. EPA on used-oil and universal-waste standards (40 CFR Part 279) and on handling contaminated automotive refrigerants (venting prohibition, recovery equipment, 100 kg/month RCRA threshold); Bureau of Labor Statistics, "Fatal occupational injuries by industry, 2023" (seven fatalities in NAICS 42314). 2009–2025. https://www.mwl-law.com/use-aftermarket-non-oem-crash-parts-repair-damaged-vehicles/; https://www.cga.ct.gov/2009/rpt/2009-R-0398.htm; https://www.vehiclehistory.gov/Data_Required.PDF; https://www.epa.gov/hw/regulatory-exclusions-and-alternative-standards-recycling-materials-solid-wastes-and-hazardous; https://www.epa.gov/mvac/handling-contaminated-automotive-refrigerants; https://www.bls.gov/iif/fatal-injuries-tables/fatal-occupational-injuries-table-a-1-2023.htm