AutoSlash is the best! It has literally saved me $1000's of dollars over the years since I've been using it. It takes all the stress out of finding the best rate. I just give them my dates of travel, book using the rates they find, and then let them track the reservation. I rest, knowing that if they find a better rate they will let me know so I never have to worry about overpaying for a car. It is the one website that I tell all my friends who rent vehicles about!