There are many ways a seller can scam you while you’re buying a used car. For the most part, you’re safer from scams when you choose to buy a car from a dealership—even a used one. But a mechanic named Mr. Long revealed one way he’s seen dealerships con used-car buyers in a video on his TikTok.

A classic dealership used-car con

Long set the scene with a basic car-buying experience. “You go in. You road test a car.” Everything seems all right. Mostly. “You like the car, except for it’s running really rough. Something’s wrong with the engine. It’s making a noise.”

Not a good scenario. You might choose to walk away, but not if the used-car salesperson intervenes first. “The dealer tries to pull the wool over your eyes with this sales tactic. ‘I’m sorry that you found it has that issue. We can go ahead and sell you the car today. We’ll sell you an extended warranty. And once this is all done, you can claim it and it’ll be free.’”

Sounds like a great deal? Not so fast. “What’s probably really going to happen is you buy the car, buy the extended warranty, make the claim, just to find out that the issue that’s wrong with your car is not covered under that warranty policy.”

Why would a dealership pull this sort of con? First, to move the car. But secondly, they probably make some money on the warranty upsell. “So you just got double scammed. You bought the car that’s broken and gave them extra money for a warranty that doesn’t even cover what’s wrong.”

This is a good con to watch out for. But I’ll add that if there’s anything obviously wrong with a car at a dealership, you don’t want to plunk down your hard-earned cash—or sign anything—until the vehicle’s ready to go.

MotorBiscuit has reached out to Mr. Long’s TikTok (@dzugus1221) for comment. You can see his seven additional situations to avoid when buying a vehicle in the video embedded below: