Many new car dealers are selling their trade-ins, at the auctions instead of selling directly to wholesalers. Look for these "fresh trades.” A "fresh trade" is a car that was traded into a new car store. These vehicles are good because they’re not dumped there because solely because they have problems, or a retail dealer is having trouble selling it, and just wants to at least break even. You'll know if certain vehicles are "fresh trades" because they'll either have a sticker on them, or they'll announce the new car store there are coming from.

One dealer car auction I go to lets you drive the vehicle down a strip of road where you can bring it up to speed. Other auctions allow you to drive vehicles around the parking lot at any time. Manheim auction, a large dealer auction chain and adesa auto auctions, don’t like dealers’ test driving the cars around the parking lot. You don't have to worry as much about test driving a guaranteed car because you’re protected. The guarantee only protects certain things such as motor, transmission, and onboard dash lights. AC, power windows, heat, and other minor things aren't guaranteed. Even if your bidding on a guaranteed car, inspect the car before the auction to see what works and what doesn't so you know what your getting into. Its not such a big deal if you inspect the day before the auction. I drive the cars around the parking lot on auction day even though I'm really not supposed too. Sometimes I get away with it, and other times I don't. I just want to protect myself if the car I'm interested in is as/is. I don't want to buy an as/is car without driving it first. I want to make sure I have a good idea of what I'm getting into.

Be careful of overheating

I've purchased cars in the past that looked fine at first, but later turned out to become a major headache. A car can seem fine going through the auction block, but can overheat by the time it gets back to the parking lot. I had purchased a BMW one time at a dealer car auction that seemed fine when I bought it. When I came to pick it up, the head gasket blew. I should have checked it prior to bidding on it. That's why now I start the cars I like, and come back later to check on them. That way I can see if the temperature gauge is starting to rise higher than normal.

Car dealer tricks to watch for

Temporarily turning off the check engine light

Many dealers will temporarily have the check engine light turned off. Anybody can temporarily turn off a check engine light with an OBD1 or OBD2 scanner. These are diagnostic tools used by mechanics. These tools are used so mechanics can find out what’s wrong with your car when the check engine light comes on. You can turn the check engine light off temporarily with these tools so you won't be able to see it on the dash when the vehicle is going through the auction block. The light will pop back on after some driving along with any other lights temporarily turned off like the SRS or ABS light. At a dealer car auction I like to attend, I found a receipt in a car for $40 for a temporary check engine removal. You can also temporarily turn off check engine light’s buy disconnecting the battery on some vehicles. These cars are usually sold as/is. If you buy a car with a guarantee, and the check engine light comes on that same day, You can bring the vehicle back and have it arbitrated.

Look to see if the check engine light has been tampered with. Turn the key so the battery comes on, but don't crank the engine. Make sure all the instrument cluster lights come on (check engine, abs, airbags). If one of them doesn't, its either been disconnected or the light bulb burnt out. I once fell victim to this scam at an auction.

How some dealers muffle engine noise

Another car dealer scam is muffling engine noise by draining the oil, and adding 50 weight heavy motor oil with Lucas oil stabilizer. They do this before running a vehicle in a dealer car auction. The vehicle has to be driven for a little while to muffle the noise but it works. Ironically very clean oil isn't always a good sign so watch out.