Speaking specifically about buying , the dealership will let you walk away without a valid driver's license if you pay for the car in full and ownership is in your name. If the car is leased or financed, you have no chance. You cannot rent a car without a license, because without a valid license you cannot get insurance. When I tried to go to Under 25 Car Rental Portland to rent a car they told me that without a license you simply can't get anything.
