I booked my car rental with Budget, using the Costco Travel website. I didn't put in our budget fast track number at the time I booked the rental. I tried doing this through Budget's website but it wouldn't let me. I called them and spoke to an operator who tried to add the number for me but told me if he did it, it would change the cost of my car rental to today's rates, which is quite a bit higher than the rate I booked through Costco Travel. Has anyone else ever ran into this issue before? I really do not want to have to go to the counter at the car rental in Vegas. I don't understand why they cannot just add the fast track number to my reservation without changing the rate. I appreciate any suggestions!