Question about using National Car Rental codes...Anyone ever have trouble comining the WWEB rate and an Entertainment coupon code? They are running a special for a full size car which spits out the WWEB code...When I add on my $20 off weekly rental coupon..I get $150 for a week..but both the Ent Book coupon and the web special says that they may not be combined with other offers..the website accepts all codes together because I get no errors and I get a final rental cost. Is it safe to assume that if the internet accepts all codes that the rental desk will take my coupon along with the special rate? I dont want to reserve for one price only to find out the coupon is no good andend up paying a higher price...