I don't know if this tip has been posted, but I saved over $200 for a weekly car rental in Phoenix by reserving a car from an Enterprise off-airport site location. The site is on 7th Ave, is VERY close to Sky Harbor, and only a $20 taxi ride. In fact, the taxi ride was shorter than it would have been to take the airport shuttle to the airport rental car location with hoards of other people. Once I arrived at the off-site location, I was in my rental car and ready to drive away within 15 minutes. The staff there told me it was more convenient to return the car to the airport rather than their location because of unreliable taxis in the mornings, so for a negotiated $20 fee (usually $30), I returned the car to the airport. The staff off-site was super friendly and helpful, and the entire process was convenient and SO much cheaper than renting from the airport.