I suggest that you get yourself down to your local DMV office and tell them you are buying a car from an estate in another state and ask what forms and documentation you will need.
Meantime, I would insist on copies of the seller's court papers that confirm his authorization to act as executor or representative of the estate.
One alternative is have him bring the car to SC and you both go to the DMV and make sure you can get the title transferred before you give him any money.
If he's not willing to cooperate or tells you more stories, then walk away from the deal.

