I go to a hand wash car wash place since there aren't any hose hook ups in my apartment complex. I buy a new microfiber wash mit each time I wash the car and I wash it by hand. Why would anyone use the brush, no matter how clean it looks to your eye? I go either real early or late in the day to wash the car by hand. I've never hand anyone give me a hard time.

With regard to water spots, I also have a black car. Polish is a sure fire way to remove the water sports, but make sure you put some type of wax or sealant over the polished area. Car covers are problematic. If you don't wash the car right before you put it under the cover, it could scratch the paint, which is a huge problem with a black car. My mom had a cover for her TT which was from Audi and for the TT and it still blew ALL over the place when placed over the car and the wind kicked up. I would try to park away from the sprinklers, even if you have to walk further. I feel your pain though, as I don't garage the crossfire either.