When you are renting a car using the coupons do you have to use a certain code or can the coupon be applied to something I find off Mousesavers? I just don't want to buy the book and then have to pay more in order to use the coupon. Also, if the book technically expires Nov 1, 2005 do some of the coupons still last past that? I thought I saw a few things that said Dec 31st. Has anyone used the United coupons that are offered? I just want to know what I'm getting myself into.