What's the best way to clean these wheels? They are EXPENSIVE and I don't want to ruin the coating. I believe these wheels are painted. I had these installed last summer when the weather was nice but after this winter there is grime / roam film on them. Is it best to just use a microfiber wash mitt and premium car wash solution versus the various wheel cleaners on the market from Meguiars, Griots Garage etc? I don't want to ruin the paint or tarnish / dull the finish. These are the Honda OEM black wheels.