Trained like used car salesmen with high pressure sales to get every penny they can out of you. "Want prepayed gas, how about extra insurance, 40 bucks a day. OK I'll sign you up for it" Before you can say no or anything at all.
On top of that Enterprise is cheaper! And don't bother calling ahead for a total price. They won't horror it and are just trying to get you in the door. Leave time to get a ride over to Enterprise when they disappoint you! Called back to talk to a Manager and they could care less what you think about your experience. Stay way!