You sound as if you are posting from the USA, but I would assume that the law is the same as in the UK, in that a bounced cheque is proof of a debt unpaid. You may well be in possession of the title for the car but if somewhere in the original agreement that you signed there is a clause that allows them to do this in such an event, you may very well have to cough up im afraid. As for the actual car itself, since you were in possession of the title, you might well have sold the car before you got wind of any of this. There's not a lot they could have done about that is there. Youv'e got the paper and the car..... possession is 9/10ths of the law.