Our black Mercedes GL450 sat out in the sprinklers one night on our recent vacation. After I washed it the spots still remain. THis car had 2 coats of Zaino Z5 on it. Why do the spots go through the wax. I ended up having to take SIP to it to remove most of them. It's frustrating that we spend so much time detailing our cars and a little sprinkler water can ruin everything.