I needed a short term car rental from and back to an airport. The lowest rates are on the internet, so I reserved a Versa hatchback, which is a damn nice car, for the remarkably low price of $8+ a day, and just $14+ total per day including all the taxes and fees. At the rental counter, I declined their fueling option, which is that I think you pay like $3.40 per gallon for a full tank and bring it back without refilling, or otherwise they charge about $5 a gallon to replenish it. I need an excuse to stop at the junkfood store when I return a rental car, so I never take the prepaid fuel option. The Versa is purported to get well over 30 MPG so after 260 miles of driving, I figured to be down maybe 7 or 8 gallons, but I got hung up by rush hour traffic and decided that it wasn't worth the risk of mssing my flight and decided to instead pay the replenishment price of $5 a gallon, figuring that my "penalty", calculated as the difference between the local pump price and the quoted refueling charge, was about $1.60 a gallon. It was worth $10 to me to make sure I make the flight, because I had a discount ticket that would be forfeited and would have to pay another $95 to catch the next shuttle an hour later if I missed this one. The attendand processed my return and laughed as he handed me the printout and said, "You only paid $14!" and I said, "It's more than that because I didn't refill the tank" and he replied, "I didn't charge you for the gas". I figured that a big national airport car rental company would have goofproofed their system such that, when they refilled the car, their accounting process would detect that there was a gas charge due, but the debit to my credit card account came through today for $14+, with no gas added. Since the gas I used must have cost them $25 to $30, they actually paid me over $10 to rent their car.