I saw this video on a car cleaning product. In it he talks about the improtance of pH balance and how it effects metals. I'm not a chemist, and it's been a long time since I took undergrad chemistry. You can see he does a little lab experiment with the metals in the various pH cleaning solutions and how it effects the metals - so in a sense the proof is in the data he shows. The questions are: - does an acidic solution cause metals to pitting? - does a basic solution cause mineral buildup? - is a pH neutral solution optimal to reduce degradation of a metal material. Keeping in mind this would be applied to wheels, the metals are going to be: aluminum, steel alloys, and magnesium alloy. I know pure magnesium reacts with water violently, so it be tamed in alloy form. I can't imagine a coating being sufficient because if it gets rubbed off or scratched the first time you drive in rain your rims would catch on fire.