Check online for coupon codes. retailmenot.com is a good source for that. Also, if you have checked a certain company, then clear your cookies before putting in the code and trying again. I have noticed that when I do that, the price can suddenly drop. Also, even if you have checked with a code, open up another window on the computer and run the price without the code. I did that last time, and found that some of the codes claimed to be giving me a discount when they were not, and others really did reduce the price. I actually found several codes online for the same company last time we were booking a rental car, and even though some of them claimed to be giving the same discount rate, the prices would come up very different. It is hard to tell if you have come up with the best rate. The same company's rate can vary widely even for the same dates. It is similar to booking airlines- the price fluctuates and you just have to keep trying until you find a price you can live with. Look and see the company's policy on cancelling. Car rentals are typically a lot easier to cancel than flights. I have booked a car before, and then found a cheaper rate with the same company, so cancelled my original booking and rebooked at a lower rate.