Only 24.5% of Top-1M Car Dealer Sites Mark Up Vehicles on Their Crawled Pages

Summary

Someone asks an AI assistant for a used Toyota RAV4 under $25,000 within 30 miles. To answer, the assistant needs inventory it can read: make, model, year, mileage, price, condition and where the car is. A local dealer may have exactly that car on its lot, listed on its own website without any of those facts in structured form.

Vehicle and Car markup let a dealer describe each unit in its inventory. Search engines support vehicle listing results, and AI shopping answers can use the same fields.

Among top-1M sites that identify themselves as auto or motorcycle dealers in markup, only 24.5% showed vehicle markup on a crawled page.

What we measured

We used four October crawls from HTTP Archive (2023 to 2026), mobile client, top-1M sites. HTTP Archive does not detect a specific dealer website platform, so we defined dealer sites as those declaring an AutoDealer or MotorcycleDealer node in rendered JSON-LD on a crawled page. We then checked whether any crawled page on the same site carries a Vehicle, Car, Motorcycle or similar node, after flattening nested objects and @graph arrays.

Field completeness uses every vehicle node found on any 2026 page and is reported in aggregate. No dealer platform is named.

Vehicle markup on dealer sites is rising from a low base

Both the number of dealer sites and the share marking up vehicles grew each year.

Of the 761 top-1M sites with vehicle markup in 2026, 230 declare themselves dealers; the rest do not use a dealer type.

Price is common, VIN and condition are not

Across all vehicle nodes in the 2026 crawl, the basics that sell a listing are fairly well covered. Identifiers and condition lag.

Without a VIN, a machine has a harder time telling whether two listings describe the same car. Without condition, it cannot answer "used" or "new" questions.

Larger dealer sites mark up more

Dealer sites by rank, 2026. The top group is small.

Most dealers in the top 1M sit in the lower tier, where three in four show no vehicle markup on crawled pages.

What this means

If you sell vehicles, make sure every vehicle detail page carries Car or Vehicle markup with name, brand, model, vehicleModelDate, mileageFromOdometer, itemCondition, vehicleIdentificationNumber, color, fuelType, bodyType, an image and offers with price and currency. Ask your website provider whether inventory pages output this and check one in a schema validator. Dealers that buy generative engine optimization services should expect this check on day one.

AI shopping answers can only recommend cars they can read. Do assistants surface your inventory when buyers ask? A free AI visibility audit shows you, and an AEO agency can then work with your website provider on the gaps.

Limits

Dealer sites are defined by self-declared AutoDealer or MotorcycleDealer markup, which biases the group toward sites that already use structured data. The share across all dealers is likely lower.

HTTP Archive crawls one homepage and one inner page per site, so many inventory pages are not sampled.

Field counts are per vehicle node; inventory pages listing many vehicles weigh more.

We count JSON-LD only.

Frequently asked questions

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