It varies by station. Where was this?

I chose a Challenger from LGA's Emerald Aisle for a free day one-way to PWM. Others have reported trying to take an Infiniti SUV off the ES in ATL, and were refused at the booth since it was a one-way. Still others have reported taking nearly new (~500 mi) cars from MCO for the FL driveout.

On the other hand, if it's a small, non-aisle facility, they will probably assign you the worst car they have and want to get rid of, Hertz style.