I became friendly with some employees at National locations and they have been very nice to me (may also have to do with the many rentals). They let me pick whatever car I want even though I reserved a fullsize. I try not to take too much advantage of that (them). But getting a luxury or minivan on a fullsize rental at a non-airport location is pretty sweet. Also, if the line is really long and I am returning, they let me just drop the keys and go, once or twice they forgot to process the return I just called and they did it over the phone (by the original return time). Plus they've given me a few extra hours here and there on the rental. Always a good idea- just have to find the right person, someone who seems somewhat inclined towards this.