Review on Spotless Car Washing System: Unger Rinse 'n' Go with Deionization Filter - Your Solution for a Flawless Finish! by Brian Rogel

I have used this device 3 times and it is very effective in washing cars with no stains. I have very hard water in my area and even after adding a softening system that still doesn't remove solids from the water this has been a great addition. From what I've read it doesn't last too many washes before you need to change the resin. So don't use it during the actual car wash, only for the final rinse (and make sure you only turn on the nozzle half with low water pressure so it has enough time to process the water flowing through). I installed a quick connect system on my hose so I can easily swap it out if needed. But I have had many problems with leaks, both at the hose connections and at the top, although I made sure everything was tight. So I just had to live with it and make sure it was outside my garage and not inside due to leaks. But other than that, it seems effective in a spot-free conditioner!