Actually, we use far less water per vehicle than a typical home car wash, and we only use earth-friendly, biodegradable cleaning chemicals.
A recent study shows that the average person uses over 100 gallons of water when washing at home, and the soap runs off into the storm drain and doesn't get treated before entering local natural-water sources. Alternatively, our express car wash uses less water, and all the soap and residue is either captured and recycled or treated before the water is returned to local lakes and streams.