I can't recall the company (Budget or Alamo) but a few months back I filled the tank before return. When I got to return center they charged me for entire tank at outrageous price per gallon because I did not have my receipt proving that I had filled the tank. Although, they could easily see that the fuel tank needle was full. The manager at counter pointed to the small print on a back page saying that this was required and when I signed my contract I agreed to provide such receipt. Again, although he could see that the car was showing full, he hid behind the small print and charged me. Warning to all of us. Now when I fill any rental vehicle with gas before returning I keep receipt so if asked I have it.