Hertz in Sky Harbor always seems to upgrade me at no charge. This week was a Camaro with 2 miles on it!!! I needed a car for 3-4 people, but could turn down the muscle car. Service here is always good, and returns seem to be fast, except on Fridays and during baseball spring training.
The offsite airport location is way, way offsite and it would be really nice if SkyHarbor put a highspeed rail link to this rental car location. (Improve upon the SFO design).