Senator Bob Corker, R-Tenn. , right, views the Chevrolet Volt with General Motors Vice President of Global Design, Ed Welburn, at the North American International Auto Show in Detroit, Tuesday, Jan. 13, 2009. AP Photo logo AP Photo 10 months ago

Senator Bob Corker, R-Tenn. , right, views the Chevrolet Volt with General Motors Vice President of Global Design, Ed Welburn, at the North American International Auto Show in Detroit, Tuesday, Jan. 13, 2009.