- cars are in constant contact with the ground and therefore can constantly dissipate any static, albeit very slowly, through the tires whereas in aircraft it builds and may not be dissipated by the time you arrive at the fuel pump.
This is the key concept. It's less the risk of static build up during the flow of the fuel in the supply line to the tank, but rather the initial charge difference possible from a plane which has just built up a large static charge during flight. You would rather dissipate that charge with the bonding cable to the airframe ground before the fuel nozzle is anywhere nearby, than between the nozzle and the tank filler neck at the moment you put the nozzle in the tank.
Bond the plane to a good (not painted) airframe ground point. I like the exhaust pipe best, as the engine is well bonded to the airframe (or you have a maintenance defect). Tie down rings are ok, if they are fixed, rather than retractable. Wheel parts are ok, with a caution: I had a fueller bond to the nosewheel of the 182 amphibian. I pointed out to him that the two nosewheel struts on the Aerocet floats are composite, and non conductive. I moved the bonding clip to the exhaust pipe.