** FILE ** Mary Barra, senior vice president for global product development at General Motors, speaks at the debut of the 2013 Buick Encore at the North American International Auto Show in Detroit on Jan. 10, 2012. (AP Photo/Paul Sancya)

Photo by: Paul Sancya

** FILE ** Mary Barra, senior vice president for global product development at General Motors, speaks at the debut of the 2013 Buick Encore at the North American International Auto Show in Detroit on Jan. 10, 2012. (AP Photo/Paul Sancya)