I would contact the purchaser, and see if you can come up with a "storage agreement". This way you would be compensated for the inconvenience of having to store the car for him. You can set a date unto which the car needs to be picked up, and also be compensated for storage time already accrued. If he is having trouble getting a shipper, include a fee to which you would assist in getting a shipper for him. Let it be known that you will be compensated for this service. He may be very easy to work with this way. Good Luck