I just had another rental where I returned the car full, but a $19.73 fuel service charge was added.

Upon closer investigation, I see that the Connected Car Sensor showed that it was 1.4 gallons shy of a full tank... unlikely, given that I completely filled it within a half-mile of the rental station.

Since I returned it after hours (to a station near my house), I had to call and fix it. Nobody answered the phone (it dumped to central reservations), so I had to drive over there. I had both my receipt and a photograph of the full gas gauge.

This is the 4th time this month that I've had to sort out something related to fuel charges on an AVIS rental.