Rental Car Magic, a personalized service that tracks rental car rates, sends e-mail alerts to enrolled travelers when a reduced price is found for the vehicle, dates, and destination that they’ve already reserved. Upon notification, the traveler simply cancels the original reservation and re-books for the new price.

Rental Car Magic unearths the lowest possible rates for car rental. After reserving a rental car, customers enter their rental information at Rental Car Magic. The program tracks the reservation and applies available discounts until the rental date begins. Customers are notified by e-mail when Rental Car Magic finds a cheaper rate that exactly matches their rental requirements.

The program takes advantage of the fact that rental car reservations can usually be modified or cancelled at no charge. Travelers can re-book a rental should a cheaper rate be found.

Rental Car Magic costs $14.95 per reservation, and comes with a money-back guarantee if Rental Car Magic cannot find a rental rate at least $15.00 cheaper.