Your buyer has asked me to pick up the car for him. Just send me your address and have a title that can be signed over to me. No need to thank me. I'm happy to help.
Seriously, if I were in your situation I would start keeping track of storage fees and ask the buyer for payment of those fees before turning over the car to him. It does seem odd that someone would pay for a car in full and not pick it up or arrange shipping. Is he having health issues or other extenuating circumstances? Good luck.