Renting a car isn't possible as I haven't learned yet andI think the US age law for driving is higher then here in the UK anywayIf you're talking about one day in another park, you can do a taxi or shuttle. But if you're talking about multiple days off Disney property, it will probably be cheapest to rent a car for a few days. You can pick up at Alamo right on Disney property if you don't want to get it at the airport.