O.K. I just did two cars this weekend.
1.) 1998 Silver/Blue Viper with last Zaino coat about 1 months ago.
A.) Washed the car with Zaino soap.
B.) Sprayed car with regular water.
C.) Used filtered water to finish to hopefully achieve a spot free finish.
** Drum roll please.....
Don't bother with this method. As most of you know, the water beads like crazy on a Zaino'ed car, and I waited 2 hours for the water to dry. At this point, the water was still beading. I wanted to take the Viper for a drive, so I gave up and dried with water blade and towel. Would it have dried spot free? Who knows... But I would have had to wait 5 hours to find out. It may have dried quicker if I used the Autodry car soap, but I did not want to take a chance of stripping any Zaino. Sal recommends only his soap, and I have to agree. I know from experience if I use another car soap the Zaino coating does not last 1/2 as long.
2.) 1989 Buick Park Avenue - Black (Excellent Condition)
A.) I followed the instructions 'EXACTLY' on this vehicle. First step spray the car off with regular water.
B.) Use the soap they provide, and spray over car. Used a chencille mitt to clean.
C.) Spray clean with regular water.
D.) Final rinse with filtered water.
** Did it work? Yes, the car did dry 95% spot free. The car looked good, but I could have achieve the same result QUICKER with my usual method. The filtered water sprays extremely slow, and by the time you rinse the car with the filtered water, you could have dried it and drank a beer. Not to mention I used almost the entire container of soap they provided with the unit.
Conclusion: I don't recommend this product. It does not save time, and the cost of filter and soap will add up over time.
My method (Unbeaten for 3 years now - I've tried everything, including electric leaf blowers): Wash vehicle. Spray clean. Disconnect sprayer from hose, and allow a steady stream of water to flow over roof, hood, doors. This will sheet almost all the water off your car. Remove remaining water with California Water Blade and 100% USA cotton Towel (I prefer Polo). I have NEVER strached my car or created swirls using this method, and it is quicker/cheaper than the Autodry system.
My .02.