Mr. Clean
The way the Mr. Clean car wash system works is that the final rinse goes through a de-ionizer, and the water that comes out is free of any minerals. The minerals present in all water (except distilled) are what leaves water spots- so if you rinse off the regular tap water with a final rinse of de-ionized water, presto- no spots. Good concept, and it works well.
I AM a little concerned about the life of the final filters- here in Ohio, we have a LOT of minerals in the water, and my first (purchased) filter seems to be brown already- after two washes.
The original filter packed with the unit is SUPPOSED to be a short-life one- and it lasted 2-1/2 washes before it was obvious that tap water was all I was getting. I'll wait and see how many washes I get with the second one, and if not enough- it's back to the towels. And- the moneyback guarantee will be called in to play.
It also seems to use a lot of soap, and the soap does not "suds" like I like it too, but it does seem to clean.