I usually just leave mine in the car.

I do wonder how much of a difference it makes, especially considering that iphones are able to continue sending out pings for Find My even when fully shut off. I figure the biggest risk would be like plugging/unplugging a connector.

There are much greater ignition hazards at a gas station though, like people leaving their engines on, filling improper containers, reentering the vehicle while filling, smoking / vaping, etc. It’ll say not to do all that, but people don’t care there eiher.