I haven't purchased my Entertainment book for 2008 yet, but in the past they always have car rental offers in them. I think even for Alamo. If you know someone with one of these awesome books - I'm sure they would give you the cupon code off of them. If not, the book is totally worth the money to buy them. I save hundreds every year and my local book only costs $25!
http://entertainment.com/discount/home.shtml