The easiest and best of the options is the Disney World Car Care Center. We frequently use this location, especially when only requiring a car rental for a part of our trip.
Disney World Resorts offer complimentary shuttle service to the Car Care Center facility, by calling the main line at 407-824-3470 and utilizing extension #1.
You are Staying Off-Site Having a car can give you so much more flexibility when staying off-site, especially when visiting the parks multiple days while off-site.
Visiting these locations and more would be incredibly inefficient without a car, forcing you to rely on others to get you to where you want to go.