like stated. you can't wash it in the sun. I know ONR helps soften water further and I am left with little to no water spots. But that is a different type of washing method where you dry the car right after cleaning a section. Try some of the "no water/rinse" washes out there that can be a very effective tool for those who don't have garages/ shade to utilize.
I'll be sending you a PM on this...
