I paid the lowest rate possible by accepting Dollar's vehicle choice. When I went to the Dollar counter in Louisville airport, I was told that I could upgrade for $15. Being in a hurry and not wanting to argue, I accepted the $15 upcharge. Receipt indicated fuel was full, but it had less than 1/4 fuel in tank. I caught it and mentioned it to supervisor before driving. He asked the three guys there if one of them would fill it up. One guy indicated he just lit his cigarette and the other 2 sitting down, looked at each other and neither responded or stood up. The situation was ignored. After several minutes, one of the 4 entered the vehicle and started to take us, then he stopped and went back to the others. After 4-5 minutes of waiting, I walked over to them, asked what was going on, and then they indicated that they couldn't fuel it up with us in the car. Then another manager came up and told them to give us an upgraded vehicle that was ready to go. It was not as new as the initial Impala offered, but a Malibu is a step up. It was fairly clean, but I stopped to clean the side mirrors, windshield and rear window just for my personal choice and safety. One of the tire valve stem caps was missing, the passenger side child lock won't disable, and the low tire pressure warning light came on a few days later, then shut itself off? The tires all looked good. Bottom line, the customer service was extremely poor and to experience all 3 employees unwilling to assist or even get up in front of myself and my daughter was disappointing.