Ageing Cars, Slower Growth: Why Auto Parts Fitment Data Wins
BCG expects Europe's aftermarket to grow just 1.7% a year to 2035 while cars get older. In a slow, ageing market, sellers grow by getting fitment right. Here is how.
The easy years are over. In September 2026, Boston Consulting Group published its outlook for the European aftermarket: growth of just 1.7% a year through 2035, down from 4.7% a year between 2021 and 2025. At the same time, the cars on Europe's roads keep getting older. Read the BCG report.
For an online parts seller, that combination matters. When the market barely grows, you grow by winning orders from competitors. And when the average car is older, getting the right part to the right car gets harder. The sellers who win the next ten years will be the ones whose fitment data is precise enough that buyers trust the first click.
What the new forecast says
The key figures from BCG's study, which covers the market at wholesale level:
Market size: from €99 billion in 2025 to €116 billion in 2035, driven mainly by price inflation rather than volume.
Car parc: 343 million vehicles by 2035, growing only 0.4% a year.
Age: more than one vehicle in three will be over 16 years old in 2035, up from 23% in 2021.
Electrification: battery-electric cars rise from 4% to 26% of the parc, cutting aftermarket growth by about 0.7 points a year.
Usage: kilometres driven per vehicle fall about 0.6% a year.
The ageing trend is already visible. ACEA's January 2026 report puts the average EU passenger car at 12.7 years old, up from 12.5 the year before (ACEA, Vehicles on European roads 2026; summary by Rematec).
Why older cars make fitment harder
A 15-year-old car is not just an old version of a new car. By the time a model has been on the road that long, it has usually been through a facelift, several engine options and production changes that alter which brake disc, filter or sensor fits. Parts get superseded and OE numbers change. Many cars have also had previous repairs with aftermarket parts.
The buyer is different too. Owners of older cars are often DIY drivers or customers of independent garages. They compare prices, and they search carefully. A listing that says "fits Golf" or "universal" gives them nothing to check. They leave, or they buy and return.
Slow growth changes the maths of a wrong part
When demand grows fast, a sloppy catalogue is hidden by volume. When growth falls to 1.7% a year, every wrong-fitment order hurts more. Each one usually costs you:
Shipping twice: out to the customer and back to you.
Handling and inspection, and sometimes a part you can no longer sell as new.
Support time on emails and calls.
A customer, or a garage account, that may not come back.
Work out your own number. Take last quarter's returns marked "does not fit", add the real shipping, handling and support cost of each, and compare it with your net margin per order.
Older and electric at the same time
The parc is ageing and electrifying at once. Your store has to serve a 2009 diesel and a 2024 battery-electric car with the same search. Electric cars drop some wear parts, such as oil filters and spark plugs, keep others like brakes, wipers, cabin filters and suspension parts, and add their own components. Hybrids carry both worlds.
The practical consequence: "model name" is no longer enough to identify a car. You need the exact variant, including engine or motor, to show the right parts and hide the wrong ones.
Five things to do this week
Pull your returns from the last 90 days and tag every one caused by fitment. Note the vehicle and the part category.
List your 50 best-selling products and check that each has vehicle-level fitment, not "universal" or a model name only.
Add OE and cross-reference numbers to those pages. Mechanics and experienced DIY buyers search by number.
Test your own store with a car that is 15 years old. Can you find the right brake pads in under a minute, on a phone?
Read ten "will it fit?" support tickets. Each one points to a page where the answer should already be visible.
Doing it with Shopify, TecDoc and Mecaparts
TecDoc, the catalogue standard from TecAlliance, already describes vehicles down to the variant level (the KType) and links parts to them. The work is getting that data onto your own store. Mecaparts connects your own TecDoc licence to Shopify:
Vehicle search by make, model and engine in every store, VIN search when your TecDoc subscription includes VIN lookup, and KBA (HSN/TSN) as an add-on for Germany.
A "fits / doesn't fit" badge, the list of compatible vehicles and OE and cross-reference numbers on every product page.
Bulk import from CSV or Excel, or direct selection in TecDoc, with rule-based categories and price and stock sync.
Storefronts in English, French, German, Spanish, Italian and Norwegian.
Mecaparts does not resell TecDoc data: you keep your licence and your data relationship with TecAlliance. See how TecDoc works on Shopify or compare the options.
Clean data also travels further
BCG expects customer access in 2035 to be increasingly mediated by AI-based platforms (Teleborsa). Whether a buyer arrives from a search engine, a marketplace or an AI assistant, structured fitment data, vehicle lists and OE numbers on your pages give machines and people the same clear answer. A vague listing gives neither.
FAQs
Does a slower market mean less opportunity online?
Not necessarily. Total growth slows, but the market is still worth over €100 billion and older cars need parts. The opportunity shifts from riding demand to winning share, and accurate fitment is one of the few levers you control fully.
Is make-model-year enough for older cars?
Often not. Older models have many engine variants and production changes. Identifying the exact variant, by engine, VIN or, in Germany, the KBA number, avoids most wrong orders.
Do I need my own TecDoc licence to use Mecaparts?
Yes. Mecaparts connects your existing TecDoc licence from TecAlliance to Shopify. It does not resell TecDoc data.
The next ten years will reward sellers who make fitment certain, not those who list the most SKUs. If you sell on Shopify and hold a TecDoc licence, you can show exact fitment on every product page. Start the 3-day free trial.
TecDoc is a registered trademark of TecAlliance GmbH. Mecaparts is not affiliated with TecAlliance.