While not particularly helpful to you in your situation now, for the benefit of others considering buying a used car, I cannot emphasize how helpful CarFax is for title and history research.
I spent about three months running down information on cars while searching for a used vehicle on EBay. You just can't imagine how many vehicles are offered for sale that have what you'd consider title or history problems. I had people tell me "it's never been repainted and never had damage" when CarFax showed a history of "severe front end collision damage". Now that CarFax is becoming well-known and easily available, people will try to explain away that "salvage title" as "well the car was briefly stolen and required a salvage title to re-register it."
Even when there are no obvious title or history problems, you gain a lot of insight about the vehicle when its been traded at the "Eastern Regional Auto Auction" every few months for the last two years!
So, thanks to CarFax, I ended up with a good used car at a great price - even from EBay. Of course, I waited until a prospective car came up for sale in my region that I could take a look at in person before closing the deal. CarFax + personal inspection is the best way I've found to buy a used vehicle.