Pat why do you say powder coat isn't resilient? It is quite resilient. WhenI was doing it for a living we did on a daily basis, horse stalls, stair railings, outdoor furniture, car frames, car and 4x4 wheels, suspension. Powder is absloutely the way to go for underside parts. I know you don't want anything non Porscher on your car but how about those tires....or that RE-paint.....
or the gas.....or the wiper blades.....