carfax is not as accurate as you'd need.

You might be able to check with the DMV. I "sold" a car to a "friend" who ended up not paying me (thus, the quotes) and I checked with them to see if he turned in the title. He did, but they were nice enough to give me his address. Of course, having no legal action I could take, I assumed it was an old address anyway, and dropped the matter altogether ):

Why are you buying/selling cars so quick before being able even to get them into your name? Find out from them what needs to be done, if anything CAN be done. Which, if you have posession of the car and the guy isn't reporting it stolen, surely you can get it into your name.

Besides, legally, you have to wait 21 days from the time you turn in the title before you can sell the car. I went through this with the Buick. Of course, it was worth it.