IMO, I would go with the black ones mostly because you have a black X3 and it should set it off quite nicely. I'm also guessing you would go with larger rims/lower prof wheels? It should look pretty "mean" with that combo.

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2006 X3 3.0i Highland Green Metallic, Sand Beige Montana Leather, Steptronic, Premium Pkg, Cold Weather Package, Privacy Glass, Xenon Headlights
2007 328i 6-speed, Black Sapphire Metallic, Sport package, Black Leatherette, Heated Seats, iPod & USB Adapter
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