What things would you ask when looking to buy a pre-owned car from a dealer?
Show me the Car Fax.
"What am I doing, giving this guy money when I have NO IDEA what kind of shape this car is in, and he just wants to unload it ASAP?"
If you mean a new-car dealership: Normally, most dealers turn older and less attractive cars over to wholesalers to sell through the used-car-lot market. They tend to keep only those which they think they can sell quickly at a premium price. So you are probably getting a decent car for a premium price when buying a used car from a dealer. And personally, I've found it fruitless to ask questions of dealer salespeople other than "Let me see the Carfax"; "Do you have the service records?" and "Can I have my own technician look at it?". For that third question, be prepared in advance, knowing which AAA shop you want to take it to, where you can have the 100-point AAA inspection done. If there are no service records (the Carfax will have those done at a new-car dealer), then worry. You should depend on your own research ahead of anything a used-car salesperson tells you. One important piece of research: look up the recall history of that model (there's a very helpful federal government website, at least until the Tea Baggers take over and ream the government). Then check the vehicle history to make sure the recalls have been done. I recently sold a BMW for which there had been a recall, which I had done, but which, if it had not been done by 2014, could cost the next owner $2,500 or more. If the car model had recalls, and there is no record of them having been done, do not buy the car.