That's one of the reasons I use only the big rental companies. If you are a regular customer, they will do things to keep you as a customer. When you shop for the cheapest, you may get it but you probably won't be recognized the next time you rent from them.

A number of years ago, I needed a big car to accommodate visitors. I shopped for the low price and rented from one of the smaller names (but one I'd heard of before). I returned it after a week and no inspection was made on return. A few days later I got a letter saying there was damage and I was responsible for the repair cost and the loss of availability of the car for a week while it was being fixed. I replied that there had been nothing called to my attention on return and I wouldn't accept any charges. Never heard from them again.

Since then, I am a loyal Avis customer and in most cases the rate they give me on a rental is within a few dollars of the cheapest on-line quote. I can recommend signing up for their Preferred Level. If you rent a few times with them, you may be upgraded to the Avis First Level. They keep your preferences on file and you don't even have to visit the counter or sign anything when you rent a car... just make an on-line reservation and print it out.

http://www.avis.com/car-rental/content/display.ac?navId=T4M03S00