Ever stop to gas up a rental car and park the car before you pull up to the pump so you can see which side the gas cap is on? I’ve certainly done it. Quick tip, look at your dashboard. The fuel gauge, there is a little white arrow next to the gas pump icon that tells you what side the gas cap is on. Sure would be nice if it was a big honking arrow like the red one, but it’s the little white one you’re looking for.
Next tip, when you pick up the car, check the fuel gauge and grab a pic if the tank is not full. This way you don’t have to pay for the gas you didn’t burn. When you go to return the car, snap a pic of both the mileage AND fuel gauge. If you gas up the car before you return it, hang on to the receipt too. I have had a rental car company try to tell me I didn’t return the gas tank full. I had a receipt to back me up, so they had to credit the charge they tried to lay on me. I have also had a rental car with a faulty fuel gauge. I snapped pics of the gauge showing 3/4 of a tank with the receipt (date/time stamped) where I’d just filled it up. I took several pics showing the faulty gauge and showed them to the folks when I returned the car. I had no issues with extra fees because I had the pictures. Also because I had the photo proof, they took the car out of service and flagged it for repair. As a result of this and the attempted fee for not fueling the car, I started snapping a pic of the fuel gauge and the odometer before I turned in the keys. I keep the pic for a few days to make sure they billed me correctly, then I’ll delete it. I have had them email me a bill and then email me an “updated” one the next day. That updated one always has a fee tacked on which I always send right back and get a credit. It doesn’t happen often, but it does happen and they can’t argue with a fuel receipt and/or a picture.