Have him sign a bill of sale and both of you sign this:
I, [seller name], Seller of the [year] [color] BMW M3 (VIN_____) ("Vehicle"), guarantee and assure the Buyer, [your name], that:
(1) the current loan held by  will be paid in full by ;
(2) [name of lien holder] is the only current lien on the car and there are no other current liens on the Vehicle;
(3) The title is free and clear of any liens, encumbrances, restrictions or limitations and that Vehicle been used as collateral by the Seller in any other transaction; and
(4) In the event that the title is not clear and free, the Seller guarantees that he will do what is necessary to clear title in favor of the Buyer and indemnify the Buyer for any and all expenses that the Buyer incurs in clearing title to said Vehicle.
Both of you need to sign and date this. Its legally binding.
Last edited by Dolittle; 09-20-2012 at 05:45 PM.