what to do if you have the "lost" car

I think the scary thing here is there is enough information out there that he was able to track you down as a previous owner of your car. I would tell this guy next time he shows up at your door step that the car is not for sale an you expect this to be the last time he shows up on your doorstep . He did not have a gun to his head forcing him to sell the car and he made a conscious decision to sell it , case closed