Many Disney guests do not realize that Alamo car rental provides a rental location right at the Walt Disney World Resort. Many times, guests do not want to rent a car for their entire vacation. If you rent one from one of the other major car rental companies at the airport, though, you will have to pick it up when you arrive and drop it off when you return home. You could also take the Disney airport shuttle on the day you want to use the car and pick it up, but this could waste tons of valuable time, during your vacation (that always seems too short, anyway).
From your resort, all you have to do is press the "Car Rental" button on your room phone and they'll come pick you up!
This gives you the opportunity to rent a car for just a single day of your vacation to visit other Orlando area attractions, experience other parts of Orlando and central Florida, maybe take a day trip to the beach, and so on.