In countries where gasoline filling is done by driver, this spark at times results in fire. Specially when the driver places the filling gun and goes back in to the cabin while waiting for the tank to be filled. The door is usually left open during this time not allowing the static current to discharge as it normally does at the time of opening the door. As soon as the driver holds the nozzle, spark flows from body to fuel lid, at the time filling there are vapors all around fuel filling area, a strong enough spark can and does cause fire.
Saw this on mythbusters and it was not busted. The myth about cellphones causing fire at fuel stations was busted.