Consider car sharing
If you are renting cars in larger cities on a regular basis or if you only need to rent a car for a few hours, look into car-sharing services. If car sharing is a fit for you, you could save money by using car sharing rather than renting a car.
With car sharing, you can essentially rent a car by the hour. In many cases, you may be renting from the car's individual owner, who probably doesn't need the car on a daily basis, rather than from a corporation. As of October 2012, there were an estimated 1.8 million car-sharing members in 27 countries, including more than 800,000 in the U.S., according to the Transportation Sustainability Research Center at the University of California, Berkeley.
Some large rental companies offer car sharing. For instance, Enterprise CarShare and Hertz On Demand offer similar services, and Avis recently purchased Zipcar, the largest car-sharing network. But there are also plenty of small, grassroots companies such as RelayRides and Getaround, which offer the same services and may be less expensive.