Forget using Alamo. I used them about 10 times last year and had to mail in documentation to get my miles 6 out of the 10. This year I have used National since they gave me complimentry membership in their Emerald Club. I have been having trouble getting miles out of them also, but the no wait is nice.
I have used National, Dollar, and Alamo at Orlando. The only way to go is National They are on airport and you have to walk about 200 feet from baggage claim to get to your car. I will be using them in December when I am visiting DisneyWorld.
JayJ
JayJ