Yeah it might be slightly or drastically noticeable. If your spraying it it will definatley be lighter. I've only ever brushed the stuff. Whenever I've lined something with that or truck bedliner, it seems to add a fair amount of weight, after all it is liquid rubber. Still worth a shot, probably won't be crazy heavy. Post up results if you do it. Doing it to wheels would be sick, they would always look good, never get chipped and ugly looking.