A new Audi E-tron is unveiled during the media preview of the 2010 North American International Auto Show (NAIAS) at Cobo center in Detroit, Michigan, US, January 11, 2010. [Xinhua]

A GMC Granite concept car is unveiled during the media preview of the 2010 North American International Auto Show (NAIAS) at Cobo center in Detroit, Michigan, US, January 11, 2010. [Xinhua]