You can add your Alamo Insider number to your reservation by going to the Alamo website and logging in there. Your Costco confirmation has two confirmation numbers, one issued by Costco and one issued by Alamo. Just use the Alamo number to retrieve your reservation and associate it with you Insider account. The big advantage of doing this is that you can then check in online and select the option to skip the counter and kiosk and go directly to the garage to pick your vehicle. You'll be instructed to print out a "Skip the Counter" ticket that's barcoded and has a summary of your reservation information. Take this with and hand it to the agent at the exit, along with your driver's license and credit card (and possibly your Costco card, which I always include so I don't know if I actually need to do this). When I do this with a standard car reservation, the garage attendant who asks me if I need assistance has directed my to the full size aisle to select a car when I ask where to find the standard cars.