I washed my car with the Mr. Clean stuff (and to be honest, I didn't use the filtered spray too much, just the normal spray).
Anyways, it dried no problem, no spots. And later on, after a bird decided to take a few craps on my Hood
(about 2-3 days after washing it) I just rinsed it off again, and to my surprise, not a single spot. The water just spread out and slipped right off. Only place there was anything was on the moonroof, but that was only noticeable when I rinsed it later on, when there was a fire, so ash and stuff mixed with it, and made it all crappy.
Anyhoo, I think the Mr. Clean works pretty well.
Oh, and all this was in more or less direct sunlight.