I am making an online reservation with National. I am using codes posted on Mousesavers (for $35 off a weekly rental). I keep getting "your coupon cannot be applied to this reservation." I meet all the parameters stated. Do you think this means capacity has been reached?
and I was having the same problem with codes/coupons for National-- until I found the ones below from carrentalsavers.com. Only catch is you need to use an American Express card. I was able to use the Amex code plus the $20 off weekends coupon and it cut my rate tremendously-- now have 4 weekend days in a midsize for $146. (YMMV as ours is a one-way rental; we are picking the car up elsewhere in FL and dropping it at the Car Care Center.)