South - Car rentals at Nashville (BNA)?

I read somewhere that some of the car rental companies at Nashville require a shuttle to get to the car, while some have the cars within walking distance of the terminal? Is this true? If so, which have the cars within walking distance?

I'm renting a car, and I'll be returning it/catching a flight with little time for error, so I'd like to avoid having to return the car at an off-site location and having to take a shuttle to the terminal.

Hertz

National is also in the terminal. If you rent from one under the terminal, be sure to keep your rental paperwork - they require ID and the papers to pull under the terminal when returning the car.