The VW/Audi Kharthum wheel is a 18x8 et 57 wheel in the Porsche CB and bolt pattern. Is there any reason these wouldn't work on the Boxster? Thinking of 18x8 square setup.
VW uses a 5X112 bolt pattern these days, the Boxster is 5X130 so it would not work without adapters. Not sure how they come in a Porsche bolt pattern, maybe not a factory wheel.