Copper, hands-down.

I immediately thought of msheredy's photoshop he did a few years back:



Now... follow me here... All silver/chrome OEM accents are changed over to copper, save for the windshield surround.... Now, do a nice staggered-fitment wheel with a substantial lip on the rear, and have the wheel face in black, with a copper lip... and, eventually, throw some nice meaty calipers behind them and paint them copper (AMG 6-pot calipers, anyone?). This would be a true head-turner.

And a head-turner like nothing else on the road.

You must do this, man...