Don't some agreements require that if you turned down all the fuel options that you return the car at the same fuel gauge reading but you have a receipt from a gas station in "X" miles of the rental location?
Then how can you fill up in NJ and return to NY?
Of course I've only been asked for a receipt once and that was for a one day rental of 6 miles (3am arrival and all cabs had left, pre-uber).