Forbes: Million-Euro Bugatti
Among the many options a Veyron buyer can order, are two one-carat diamonds, cut with 16 sunray facets (16 being the number of cylinders the engine features). The two diamonds reside, respectively, on the speedometer needle, and at the center of something Bugatti calls the "powermeter."
(Thanks to the MO for pointing out this gem. Ahem.)