I found a VERY detailed review of the spotless car wash.
I ran a true side by side comparison test. I have a Firebird Trans Am which has five coats of Zaino Bros. show car polish. One half of the car I washed with Mr. Clean AutoDry, and the other half with the Zaino Bros. car wash.
Before we get to the results of the test, let me take a moment to explain how the system works. In the picture above, the blue object is the spray nozzle, which sprays soap, unfiltered water, and filtered water. The small container to the left of it, is the special AutoDry soap. Finally, the container completely to the left is the water filter. The spray nozzle has a reservoir for soap, so you put about half the soap container in this reservoir through a small hole on the side of the nozzle. There is a rubber flap with a lip that seals the soap fill hole while in use. The water filter slides into the rear of the nozzle, after you open a door on the rear. Inside the nozzle, there are two short pipes which fit into the water filter. When you select filtered water, the water goes in one side of this filter, and out the other to the nozzle head. On the side of the nozzle is a sight glass (really plastic), which changes color (darkens) as the filter become full of water impurities. It is good for about three car washes.
Using the AutoDry nozzle is easy. It connects to a garden hose, just as a regular spray nozzle would. You turn the control knob on the top to the left for soap, middle for rinse, and right for filtered rinse. There is a switch near the handle to turn the water on and off. You cannot adjust spray pressure with the AutoDry nozzle (only on and off).
First you wet the car with the control knob set to the middle Rinse position. I try to spray off any large chunks of dirt, so it will scratch the paint later, while running the sponge over it.
Then you set the nozzle to the left Soap position. After soaping, you use your sponge to wipe down the car as you would with a regular bucket of soapy water. Here is where I deviate a bit from the AutoDry instructions. If you don't thoroughly rinse the sponge, you are going to be scraping the dirt on the car as you wash. I brought out a bucket of clear water to rinse the sponge occasionally.
Then you set the dial to the middle position to rinse the car with plain water.
Finally, you turn the dial to the right Filtered Water position to do the final rinse. The filter removes dissolved solids (minerals) to reduce spotting.
The AutoDry side was allowed to dry without toweling, while the Zaino Bros. side I dried with 100% cotton towels per their recommendation. I also washed the wheels, inner wheels, fender wells, and undercarriage with both products. I tested AutoDry in the engine compartment, too. Yes, I am very particular about how my car looks.
There have been reports of AutoDry removing polish, and also leaving a haze. I figured a side by side test was the only true way to test for this.
1) AutoDry did NOT remove the Zaino polish.
2) After drying, I viewed the car in both the shade and sun. I did NOT detect any haze on the AutoDry side compared to the Zaino Bros. side.
3) AutoDry did leave some water spots on horizontal surfaces. It appeared that the Zaino polish caused some of the water to bead, even though the surfactants in the AutoDry soap try to eliminate this.
4) If the AutoDry soap was VERY thoroughly rinsed, beading appeared to occur more frequently. Again, too much of the surfactant was removed.
5) The washing system AutoDry recommends, without a sponge bucket, leaves excessive dirt in the sponge, which could cause fine scratches. I used a bucket with clear water to rinse the sponge out regularly, and then applied the AutoDry soap to it.
6) Some tiny water spots appeared on windows.
7) Water spots which did appear on the AutoDry side, were lighter and easier to remove, than those which occurred with just plain water rinsing.
8) Touching up the AutoDry side, to fix missed areas is tricky, because soap and plain water ends up in already dried areas. That results in water spots. To do it right, you really have to do the three step procedure with the entire car again.
9) Wheel well and undercarriage cleaning worked quite well with AutoDry, since these areas are often difficult to towel. I used the muffler for one of the tests. First I used the regular Zaino car wash and water. Spots appeared when dried. I repeated with AutoDry, and although spots appeared, they were so faint, most people wouldn't notice them.
10) AutoDry did not work well in the engine compartment, because there were too many areas which collected water. Remember, AutoDry works by preventing beading.
11) I found the AutoDry Rinse (unfiltered) water nozzle to be too strong for my comfort as far as protecting the finish. It really blasted out. The Soap and Filtered settings water flow rates were fine. I hope in a future version of the product, they include some way to controlling the flow rate.
12) I also tried a leaf blower for drying a section of the AutoDry side, which was beading, and the Zaino Bros. car wash side (without toweling). The results were equally good, and the finish had almost no water spotting.
13) The AutoDry soap did not seem to have much lubricity, and the sponge seemed to drag on the finish.
From the testing, this is a great time saving product for the average car, which typically gets little or no polish applied. I would recommend washing the entire vehicle at one time, and to wash missed areas the next time you wash (otherwise areas around it will get spotted by soap and plain water). I would avoid the AutoDry procedure for cars with meticulous detailing, and with lots of polish (although see below on how to use the part of the AutoDry system to detailed cars). AutoDry just can't do a 100% job of preventing beading on new, high quality polish. AutoDry might be helpful for cleaning undercarriages of detailed cars, because toweling is difficult there. The filter could also be handy for people washing in areas hard water, even if you use your regular bucket of soap, and towel dry.
Update! ...for the Auto Enthusiasts:
I ran some additional tests with my Zaino Bros. regular soap, and AutoDry filtered water. I bought a Black & Decker 230 mph electric leaf blower for drying, their most powerful unit. Here was my procedure - (1) wash the car normally with regular car wash soap, (2) rinse the car normally with regular hose water being sure it did not dry at all (to prevent spotting), (3) rinse the car with the AutoDry filtered water (control knob turned to right), being sure to "sweep" unfiltered water down the car with the flat spray pattern, thus leaving only filtered water behind, and (4) drying the car with the Black & Decker leaf blower with included concentration nozzle attached.
The results? No time saved over hand drying, BUT I had absolutely no spotting, and the car came out better than it ever has with just plain water rinsing and hand drying with 100% cotton towels. The advantage of this procedure is the leaf blower allows you to blow water from hard to reach areas such as inside left and right mirrors, and around lamps, so they don't drip later (with spotting) after you've finished drying the car. The other advantage is the filtered water is less prone to leave spots. I have done this three times now, and the car comes out fantastic. Also you reduce the potential for scratching, because the car is not dried with towels which can pick up missed dirt. This my new car washing procedure. My only other recommendation is try to do this when your neighbors aren't home, so you don't drive them nuts with leaf blower noise. Although I am not using the AutoDry soap, the water filter is an excellent car washing tool on its own, so I have raised my rating from 3 to 4. Good luck, and have fun!
66 mustang real street
302 4-speed 289 heads
10.63 @ 129.3