Most cars now have a flap (metal) that is pushed out of the way by the nozzle, grounding the nozzle in the process. The hose is shielded. Aircraft pick up static whilst airborne, their tyres don't ground it so it is more likely to get a spark. I use cans to fuel from, it's a good idea (essential) to place freshly filled cans on the ground for a while to let the static dissipate before up-ending them into the plastic funnel. Especially if they have been sliding around on the carpet en route. Also make firm contact between yourself and the airframe, don't stand with the nozzle held at arms length gushing fuel into the filler from a distance.
Just my opinion.