I have used Auto Slash several times. Like others, I was skeptical at first until I used it the first time. I am able to get better rates from Auto Slash then I can get from Costco who always had the best prices. I still check other sites but so far Auto Slash beats almost everyone's prices. In addition you can submit your booking information and they will notify you if the price goes down. Can't beat that for a FREE service!

Auto Slash was recommended to me by a friend. I tried them out and the first time I kept getting emails up to the date of my rental. At that point they had saved me nearly $100.