National is now only at the Dolphin - Alamo has a desk at the Dolphin and the CCC.I think it is Alamo (which partners with National). If you rent from there, check their operating hours. We reserved a car and got to the Dolphin location 5 minutes after they closed (which was 4:00 pm) and had to make other arrangements to go to the other car care location at WDW. Other than that, it is very convenient.