22.6% of dealer listings change price after they post. That changed what we build.

When we started AutoLander, we treated a Facebook Marketplace listing as finished the moment it went live. Take a dealer's inventory, turn each car into a listing, post it, move on.

Then we measured what happens after. Across 10,798 dealer listings we could compare over time, 22.6% carried a different price later than the one they posted at. Sold cars have the same problem: the dealer's system knows a car delivered on Saturday, and the ad keeps running until something takes it down. Every figure in the report is public under CC BY 4.0: https://autolander.ai/facebook-marketplace-used-car-report-2026/

So most of our engineering time now goes into syncing inventory (74,000+ vehicles so far, from 316 dealer inventory feeds) and keeping the listings made from it in step, and much less into the moment of posting. Three rules came out of that work.

The dealer's record wins. When the listing and the dealer's own system disagree on price, the ad changes to match the record, never the other way round.

Unknown stays unknown. If a feed doesn't give us a used car's mileage, we don't invent one, and the car waits to post until it has a real reading. A made-up number on a car ad does more harm than a late listing.

The AI only changes the scenery. Dealers have run 94,000+ photos through our background replacement, and the failures that mattered were always to the vehicle itself, so the car is cut out first and composited into the new scene, never repainted.

Where we're still limited: we're only as fresh as the dealer's feed. If their feed runs late, the ad runs late, and that one is ours to own. Our numbers also cover dealer inventory from 196 US stores only, so they say nothing about private sellers.

A question for anyone who syncs one system into another they don't control: how do you size the window where the copy is allowed to be wrong? We sync each feed on a schedule and refresh a car's details right before it posts, and there's still a gap between syncs where the ad and the record can disagree. Curious how others close it.