Rental. When I went to get it they tried to talk me into getting a car that would have cost $20 more per day. I said no, they kept talking about how great it was, I said no. He took me outside to show me how nice the car was. I said no. Finally he admitted they didn't have any cars in the class I was authorized for and he had to upgrade me to the more expensive car for free.
It's not just airlines. It's corporate America.