Wheels changed color

[Cbonilla]

Are you sure these wheels aren't painted with a clear coat. Unpainted aluminum will tarnish rather rapidly. As far as I know Boxsters all had painted or clear coated wheels from the factory. My BBS wheels have clear coat over polished metal wheel lips and painted/clear coated centers.

Rather than a metal polish I'd recommend a wheel cleaner (non acidic) and a coarse sponge, assuming that you haven't damaged the finish with the polish

CB