Dave is absolutely right! Back in 2008 when I bought my 2002 Mustang it came with aluminum wheels but not a matched set. They were beat to death with a lot of scratches and peeling clearcoat. The clearcoat had turned yellow and made the wheels look horrible. I bought an aluminum polishing kit from a company called Busch at the Ford show at Carlisle. This aluminum polish was so strong that it made the peeling clearcoat even worse!
I even spoke with a wheel repair specialist who told me how expensive it would be to have the clearcoat removed.
At that point I decided that it was easier for me to just buy new wheels for the car which I did. The Mothers Powerball System is better suited to chrome finished wheels which in most cases are not clearcoated. I would have to say that most factory OEM wheels are clearcoated to offer them a measure of protection against pitting. If you want to use the Mothers Powerball system you can do so with a liquid cleaner/polish/wax. Mothers makes a product like this as does Meguiar's, Armor All, Turtle Wax, Black Magic, Simonize and many other companies.
It is just so much easier to use a car paint protectant cleaner/wax which is mildly abrasive and will not harm the clearcoat on your wheels. If it is safe enough to use on your cars paint than it is safe enough to use on the cars aluminum wheels. You can use a Caranuba based product or a synthetic product but both would be safer on your wheels. I use metal polish but not on my wheels.
Midnight Blue
MCOM Treasurer-Historian