I don't think anyone will have a problem with the no longer valid codes. If you have a reservation and it confirmed it, your in. Do you really think these checkout clerks care what price your paying?? They care if you have a valid license, creditcard and if your returning the car full with gas or refueling thru them. My friend is a travel agent and she said that she has never encountered a special travel agent secret code to reward her for booking cars thru their company. I really think these codes started with visa promotions and that is why they include the insurance. My American Express has travel insurance if I book my tickets using my American express card. No code necessary--it just appears! Think about all the different visa cards out there!! What about the prepaid tolls that some rental car companies offer. Marketing tool? Do you tell them how many times your going to go thru the toll plaza? These rental companies definately are not losing money!