Thanks to dealership make ready the OEM painted wheels on my CTS are either stripped or stained by acid. Not wanting to make them worse I've yet to try anything abrasive. Is this fixable without stripping?
I clean the stained aluminum wheels on my truck with Protect-All. Works quickly. Spray on let sit a minute or two then use a soft cloth to wipe of the product. My wheels looked just like yours. Mine get stained from rain. Frequently after a rain I don't drive for several days and the rain sits there,along with the dirt that comes with it. This IMO is what makes these stains.