It has Been my experience with filling tanks on Aircraft, motorcycles,autos that the danger is the vaporized fuel above the tank outlet which is the danger. The nozzle and tank when touched together emit a spark which ignites this vapor. The screen is to prevent the vapor from forming! You would be better off grounding the car to the pump before removing the cap! In aviation you must use the grounding method to dissipate the charge that is built up on the aircraft surface!
In all honesty it is my firm belief that grounding your car by touching the pump and your car at the same time has the same effect. Draining off the static charge through your body! This is the same thing that happens when you shuffle across some carpet and touch the light switch and you are zapped by the small screw that holds on the cover plate, you are being grounded to that screw!
But then I have only been at this for the past 65 plus years,starting with the old pump up gravity flow pumps in Stinson's, Luscombe's,Pietinpols Stearmans,as well as Harley's Indian's Triumph's, Matchless, Yes A Models, 1928 Plymouths,and on and on, but I sure as heck am not going to crawl in a hole and stop doing anything that the present ALL KNOWING POWERS tell me that is Dangerous