Reserve Extra Early - No matter the car rental agency, if you make your car reservation as far ahead in advance as possible, you increase your chances of getting the best deal. Car rental rates tend to increase dramatically over the holidays and even during the summer months, so if you plan to travel during any of those times, make your reservation well ahead of time - this will save you money!
Do Repeat Business - If you tend to rent cars from the same rental car agency, make it a point to mention that when you make your reservation. Many car rental companies will offer additional discounts to frequent renters; many of these discounts are not advertised, but it doesn't hurt to make your case about being a loyal, frequent customer.
Check Online Rates - Normally, online rates tend to be a little cheaper than the normal walk-in/telephone rates. Also, most car rental websites offer additional coupons and discounts that can only be accessed and used when reserving online.
Sign Up For E-mail Notices - Many car rental companies offer the option of signing up to receive periodic e-mails that contain info on special rates and deals on car rental reservations. Many of these e-mail notifications will also include special coupons to use towards your next car rental. Many of these special deals and coupons include things like free car rental upgrades and free additional car rental days.
Check Online Travel Companies - Websites such as Priceline, Hotwire, and Expedia often have good deals on car rental rates. Simply log into each website and type in your relevant car rental info. Be mindful that most of these travel sites add a small fee onto the rental car reservation fee, so be careful that your final car rental reservation is still cheaper than it would be without using their site. It pays to shop around, even when using these specialty online sites.
Rent From High Volume Agencies - Most of the time, although it can vary, the cheapest rates and deals are to be found at the larger car rental agencies, normally those agencies found at or near large airports and metropolitan centers. These types of locations normally have cheaper rates than do the smaller, street-side rental locations.