entertainment book coupons--national counter?

[madge]

I am in the process of booking a rental car with National--when I type in a coupon rate code it kicks me back to the counter every time--is this a big deal? I'd just as soon use the Emerald Reserve or whatever it is called now, less hassle with 3 wee ones. Any suggestions?

 

[zcomic]

I had the same thing happen to me with the 2 car upgrade coupon in the entertainment book but it didn't do that with the other coupon, the one for $20 off. The difference between the two coupons on the final price was about $1 so I used the $20 off one so I can use Emeral Reserve