With Carrentals.com Search, Compare and Save Using the World's Biggest Online Car Rental Service. More cars. More locations. More value. CarRentals.com works directly with many car vendors to offer value priced car rentals at over 15,000 locations. Find savings with CarRentals coupons and sales on one-way car rentals, as well as off-airport and on-airport locations in thousands of cities. With Special Low Rates and exclusive car rental coupons and discounts, it’s easy to find cheap rental cars for every occasion with Cash Back at WaffarX. Book Today Online & Save.