Another opinion
The AutoDry system does do what it claims, but like everything, there's another side to the story. Here's what I found, just my $0.02 worth.
The filter does indeed keep out the minerals that cause hard water spots, but the filers end up being rather expensive.
Not drying the car (I like to use terry towels) inevitably will not results in the same quality wash job as drying will.
Drips that may come from the hose -before the filter- WILL water spot the finish.
The whole attraction to this system for me was to accomplish a rapid wash on my daily driver. Rapid meaning a time savings over the current process. Here to me is where any advantage of not having to dry gets "washed away", no pun intended. To rinse the car, you have to use the spray head on the "filter" setting. On the filter setting, the flow is extremely fine and low volume, and it takes many more minutes to thoroughly rinse off the vehicle than using a regular hose. So many more minutes in my experience that the overall time to wash a car with the supposedly "more expedient" AutoWash system is MORE than the standard bucket+sponge+high power rinse+terry towel dry, assisted on the horizontal surfaces with a California Water Blade. And, the "old fashioned" way will always yield the best wash. That's my take, others certainly will have experiences that may vary, but to me, all my vehicles deserve a nice towel dry.