Not rolling the dice on that and dealing with a dispute like the OP. And no, I always fill up the car when I return it. I can see the price of that up front.
My BIL had a rental Mustang and hydroplaned on I-15 going back to the airport after Easter. Totaled the car. They are still trying to settle that. A few extra bucks and he wouldn't have had to think about it again.