If memory serves, I had to "goofy-code" a National reservation back in high summer of last year at a certain airport just to get a weekend rate that wasn't three figures per day all-in. Rental rates at a few airports had really gone crazy around that time (even with $3.50 gas!). The code included insurance and was said to be targeted for non-U.S. residents.

I took an avoid-human-contact approach, pulled rank to go to Emerald Aisle executive selection (with a midsize) and had the guard as the only point of contact. Which worked OK. YMMV.