I've wondered many times how it would work to wash your car in the rain. Being in So Cal it doesn't rain too often, so when it did a week ago I tried it. Put on my "Hawaiian rain suit" and went to work. By the time I finished washing all the soap was gone. Pulled it into the garage and dried it off. Best looking wash job I've ever done. No water spots, not one!

 

Here in Vegas, it never rains. But the last time it did I took my car out and did the same thing - washed in the rain, brought it in to dry. It looked fantastic. I think the difference might be in the extra help from the rain rinsing the soap (less hard water from the hose needed). In Vegas at least, the water is hard enough to chew practically.

Rain washes will become a practice for me whenever it rains here now