Hi Sprout!
You will just need to head to the level where the car rental counters are located and go out to the National/EA in the garage. Pick out a car from EA or one from the category that you've rented, whichever. (also, there are two EA's at the airport..if one is empty...walk to the other side..its a bit of a trek but not too bad) At the window, you will need your drivers license, any coupons you may have used...and your EA card or at least the number and credit card. I have never in 13+ rentals been asked for proof of insurance and I use them very frequently. As long as you are covered via your personal ins or thru your CC you should have no problem. I also let them refill the tank because the charge is usually about what the gas station would charge anyhow so why waste time refilling my tank? I'm too busy siteseeing...lol
It shocks me to see that someone had a bad time with EA (the previous poster) because I have never ever had a problem with EA or any employee working on it. They are always the utmost courteous with me. The last time I found an empty EA (about 1 yr back) they told me to take an SUV, so of course we did!

As with any type of establishment (whether car rental, hotel, etc) if you encounter anything unsatisfactory, ASK TO SPEAK TO A MANAGER IMMEDIATELY! (and for the record, the longest I have ever been out at National in the garage is approx 15 minutes, I have never waited any longer for a car) I can usually get our luggage, find a car, check out...and I am out of the airport in less than 30 minutes from touchdown of the plane! Its wonderful!
Just always remember, like my grandmama taught me...you will catch MORE flies with honey than vinegar anyday....!
have a great trip!
E
