Parts Availability Index: Which Model Years the Aftermarket Actually Supports

We analysed 22,785 listings in our supplier catalogue to answer a question nobody publishes a free answer to: which vehicle model years does the aftermarket actually support? The answer is narrower than most drivers assume, and it is centred on a car that is already 13 years old.

• 2013Model year with the widest parts coverage
• 3,242Parts fitting that model year
• 84%Of coverage serves vehicles 10 years or older
• 2.9%Of coverage serves vehicles 5 years or newer

The headline finding

Aftermarket parts coverage is not spread evenly across the vehicles on the road. It is concentrated in a window roughly 15 model years wide, running from 2004 to 2018, and it peaks at model year 2013.

That peak is worth sitting with. A 2013 vehicle is 13 years old in 2026. According to S&P Global Mobility, the average age of a vehicle in operation in the United States reached 12.8 years in 2025 and has risen for eight consecutive years. The point of maximum aftermarket support and the average car on the road are the same car.

That is not a coincidence, it is the industry working as designed. Aftermarket manufacturers commit tooling to a platform once two things are true: enough units exist on the road to justify the run, and enough of them have left warranty that owners are paying for repairs themselves. Both conditions arrive around year eight, and they hold until the platform starts being scrapped in volume.

The support curve

Read from the left, coverage climbs steadily through the late 1990s and 2000s, plateaus across the early 2010s, then falls off a cliff after 2018. The fall on the right is much steeper than the rise on the left. Support arrives slowly and leaves slowly, but the arrival lag is the sharper effect, because a platform has to earn its tooling before anything gets made for it at all.

The new car cliff

If you own a recent vehicle, the aftermarket is mostly not there yet. A model year 2024 vehicle has 54 fitting parts in this catalogue, which is 98 percent below the 2013 peak. A 2023 vehicle sits 94 percent below peak. Even a five year old 2021 vehicle, well out of the showroom, is still 69 percent below peak with 1,014 parts.

The practical consequence is a pricing one. For a vehicle under about five years old, the dealer parts counter is often the only source for anything beyond filters, wipers, brake pads and batteries. There is no competing supply to hold the price down. Owners frequently read this as dealers being expensive, when the more accurate reading is that no alternative has been manufactured yet.

The old car slope

Going the other way, support fades rather than stopping. A 1995 vehicle still has 680 fitting parts here, 79 percent below peak but a long way from nothing. A 2000 vehicle has 1,373.

What changes as a vehicle ages is not whether parts exist but which parts exist. Mechanical and service items stay available for decades, because they are often shared across many platforms and because the specifications are stable. What disappears first is anything specific to one body: mirrors, grilles, lamp assemblies, interior trim and dash pieces. Those are moulded for a single model and nobody re-tools them once the platform is old enough that most damaged examples get written off instead of repaired.

This is why an owner keeping a fifteen year old car running usually reports that the mechanical side is easy and the cosmetic side is impossible. The data agrees with them. If you are running an older vehicle, our cooling, suspension and drivetrain ranges reach much further back than the body and exterior range does.

Coverage by make

Across 36 brands named in product titles, the ranking mostly tracks how many of each brand are on US roads, with one clear exception.

Toyota and Ford leading is what fleet share predicts. BMW placing third is not. BMW sits well below Chevrolet, Nissan and Honda in US registrations, yet it carries more catalogue listings than any of them here. The explanation is demand mix rather than vehicle count: BMW owners modify and maintain at a higher rate, and a catalogue weighted toward enthusiast parts reflects that. Read the make table as a map of where parts demand is, not where vehicles are.

What the parts cost

Price dispersion inside a single category is the number most buyers underestimate. The table below shows the median price in each top level category alongside the 10th and 90th percentiles, and the ratio between them.

The spread column is the useful one. In Drivetrain the 90th percentile item costs 90.5 times the 10th percentile item, $6.80 against $615.26. A category with a wide spread is one where the words on the box hide an enormous range of what you are actually buying, and where reading the specification carefully changes what you pay more than shopping around does.

Narrow spreads work the other way. Where the ratio is under about four, the category is commoditised, the products are close substitutes, and price comparison is a reasonable way to shop. That is most of what people buy routinely.

Buying a used car with parts in mind

Most used car advice weighs mileage, service history and reliability ratings. Parts availability rarely gets a mention, yet it decides what the next five years of ownership cost more directly than a reliability score does. A car that never breaks is cheap. A car that breaks and has six competing suppliers for the failed component is also cheap. A car that breaks and has one supplier is not.

The curve gives a practical rule. A vehicle currently between about eight and twenty years old sits inside the window where competing suppliers exist, prices are held down by that competition, and a failed component is a routine order rather than a hunt. In 2026 that means roughly model years 2004 through 2018 are the sweet spot, which is also where most of the used market sits.

Two checks are worth making before you buy, and both take minutes. First, search the specific year, make and model against a parts catalogue and see how many results come back for a body panel or a lamp assembly, not for an oil filter. Filters fit everything, so they tell you nothing. If the body and lighting results are thin, cheap cosmetic repair is off the table for that car. Second, check whether the platform was sold in volume in your market. A model that sold well has an aftermarket. A niche import of the same age often does not, however good the car itself is.

The same logic applies in reverse when you sell. A vehicle that has aged past its support window is harder for the next owner to repair economically, and that shows up in what they will pay.

Method and limitations

The dataset is 22,785 supplier sourced listings from the PartSmith catalogue. Model year fitment was parsed from product titles, for example a title reading “for 2000 to 2007 GMC Yukon”. 8,004 listings state a year range in the title, and only those enter the coverage curve. Parts with no stated range are excluded rather than guessed at. A listing covering 2000 to 2007 counts once for each of those eight model years, so the curve measures breadth of coverage per model year.

Four limitations are worth stating plainly, because they bound what this data can support.

First, this is one retailer’s catalogue, not a census of the aftermarket. It shows what one large supply chain carries. Second, the mix leans toward accessory, enthusiast and repair parts rather than the full OEM replacement range, which is why BMW ranks as highly as it does. Third, coverage counts distinct listings, not stock depth or units sold, so a model year with many listings is not necessarily one with many parts shipped. Fourth, roughly a third of the catalogue states fitment in the title, so the curve describes that third.

None of those caveats move the headline. The peak sits at model year 2013 across every way we sliced it, and the collapse after 2018 is far too large to be a parsing artefact.

Questions

What model year has the most aftermarket parts available?

Model year 2013, with 3,242 fitting listings. That is a vehicle 13 years old in 2026, almost exactly the average age of a car on US roads. Coverage holds at half of peak or better from 2004 to 2018.

Why are there so few aftermarket parts for new cars?

Manufacturers tool up for a platform once enough units are on the road and out of warranty to justify the investment. A 2024 vehicle has 98 percent fewer parts available here than a 2013 vehicle, so owners of nearly new cars are largely buying from the dealer because the aftermarket has not arrived yet.

How long does aftermarket support last for an older car?

It fades rather than stopping. A 1995 vehicle still has 680 fitting parts. The squeeze falls on body and interior trim specific to one model, while filters, belts, hoses and brakes stay available for decades.

Is aftermarket parts availability the same for every brand?

No. Toyota and Ford lead here, followed by BMW, Honda and Ram. Fleet share explains most of the order, but enthusiast demand lifts some brands well above their registration share.

Can I reuse this data?

Yes, under a Creative Commons Attribution licence. Use it in an article, a video or a research note, with a credit and a link to this page.

Analysis by the PartSmith Co. parts and fitment team. Based on 22,785 catalogue listings. Method and limitations are described above, and the underlying counts are published as CSV so the figures can be checked. Browse the full parts catalogue.