A valid question for sure. We don't have issues with water spotting here so I haven't had a good chance to test for that. I let black cars air dry in the summer! Client called and said there is some water spotting after he washed it and then attempted to dry it by driving fast. The water in his area is dreadful and will leave spotting if allowed to sit on the car for even a couple of minutes in the sun. I sent him some supplies so we'll see what happens after he washes it.
Ken - Absolutely beautiful work in such a short time ! That paint was definitely a Poster Child for the local Swirl-O-Matic Car Wash people ! Great place to work and bring the family - looks so perfect up there - you might convince me to come across that border sometime! Believe its only about 75 miles from where I live to Vancouver.. Hmmm.... Thanks for sharing ! Dan F