thats cool. ive never used a foam gun to wash. the reason is because i dont get to choose a shaded time of day to wash my cars...whenever i have time sun or cloudy is when i wash my cars.
so foam would dry too fast while washing in the summer sun.
and for those that think
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washing in the sun.. lol i do it all the time without getting water spots.
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haha there's some trick to it though.