I was just there two weeks ago. National and
Alamo are together and all went fine. There were plenty of signs directing us to the correct door to catch the shuttle. The shuttle pulled up as we walked out of baggage claim. We were at the rental facility in no time.
It is a little hard to find and my GPS would not recognize the exact address, so pay attention as you leave so you can find your way back.
Have a great trip. FYI, if you have Emerald Club, their selection was pretty nice. I am Executive and was able grab a mini-van.
Duds