Most of the static electricity is generated by the person sliding across the seat fabric. That’s why you should stay outside the car while filling-up. When you’re filling a gas can, place it on the ground so it will be grounded (esp. if it is a metal can). Plus, if you overfill the gas can, you don’t want it to be inside the vehicle.
Not arguing. I just don’t see grabbing the door handle, opening the trunk(or whatever) grabbing the gas can and and grabbing the pump nozzle as not discharging the static electricity from getting out of my seat (which I don’t have to slide across). Nor does anyone else have to slide across.