no title
If you want to buy a car with no title, it is always prudent to bring the vin number, year, make, model info to your local donut shop. Eventually you will find a state trooper, highway patrolman, deputy sherrif, police officer, etc. Oh, and bring your younger sister.
Make sure you both get in front of him in line. Order your coffee, mocha latte, donut, whatever, they say "I got his" and point to the law officer.
He will, of course, refuse, but now you have the chance to start a conversation; Hey, I'm thinking about buying my little sister an old car, how do I know if it is stolen or abandoned"? He'll reply, "oh its pretty easy. all we need to do is enter this information into the handy dandy police computer gizmo."
Bing. Your off to the races.
OK, I'm kidding about the cop and your sister. Unless your sister is Salma Hayek...
Bring the vin and model info to the DMV or your local police station. If the place ain't falling down, Im sure someone can help you find out if the car is legit. Might even give you the last registered owner's contact info, where you can start your quest for a lost title.
If there is no vin tag at all, walk. If the car is stolen, abandoned, or anything else weird, walk.