General Motors CEO Mary Barra speaks next to the Chevrolet Bolt EV electric concept car (L) and the 2016 Chevrolet Volt hybrid (rear) after they were unveiled during the first press preview day of the North American International Auto Show in Detroit, Michigan

General Motors CEO Mary Barra and Alan Batey, President of GM North America, pose next to the Chevrolet Bolt EV electric concept car after it was unveiled during the first press preview day of the North American International Auto Show in Detroit, Michigan

General Motors CEO Mary Barra speaks next to the 2016 Chevrolet Volt hybrid during the first press preview day of the North American International Auto Show in Detroit, Michigan

General Motors CEO Mary Barra speaks next to the 2016 Chevrolet Volt hybrid during the first press preview day of the North American International Auto Show in Detroit, Michigan