Washed the wife's car (black) and my car (dark blue) and the water drops left almost a cement like marks when dried. I did use a blower to try and remove most of the water but still some was left. I had to pull the buffer out and lite polish to remove it. I like to wash my own cars as car washes here are $20+++ each time. I saw a filtering system on Autogeek for about $149...there are bigger ones for well over $400 but that is crazy.