NEVER EVER BUY A CAR WITHOUT A TITLE!!!!! You are in a pickle. Mechanics lein will not apply. You will have to go to small claims court. Threaten to go to court unless he produces the title. Im sure that if he is that kind of guy even if you went to court you will end up losing in the end. It will be hard and take a long time before you see any money back. If you will PM me the car/vin number/previous owner, I will go onto the GRATIS website and do a title search and find out exactly whose name the vehicle is registered under. I have access to the GRATIS site from my office( I sell cars) so it won't be any trouble.