Order the certificates from Airmiles as soon as you can. Make your Alamo reservation when you find a rate you like. You don't need the certificate(s) to do this. Once you're received the certificates in the mail (typically takes 1-2 weeks for us) call Alamo to have the certificate number(s) added to the reservation. Then, when you get to the Alamo desk at the airport just hand them the certificates and you're good to go. We've done this with our last three reservations and never had a problem picking up the car in Orlando.
- Mike