I recently purchased (as I do every year) the $50 certificates for Alamo from the Discover America Daily Getaways sale. Today while making a reservation online to use my 1-2-Free certificate, I realized that there is an option to add up to 3 coupon codes. I wonder if these $50 coupons can be applied on national as well. I seem to recall an agent at Alamo being able to pull up a future reservation I had made on National so I guess their back end systems are likely the same.

Anyone tried it out?