How did you register the car to your name without title? Or you just do not register to save sales tax? I know you bought it because it cheap than any other car you have seen, right?
To tell you the painful truth, you are not going to get your money back! Yeah, you can sue that guy if you know where he lives. But it is is civil suit so you have to hire a lawyer and wait for a few years. Guess what? Your attoney fee will be more than what you pay for the car. Plus even if you win, that guy will not have money to pay ya!