The new Mercedes GLE Coupe is revealed during a preview event for the media, ahead of the 2015 North American International Auto Show (NAIAS) in Detroit, Michigan, January 11, 2015. (Photo by Mark Blinch/Reuters)

Chairman of Daimler AG and Head of Mercedes-Benz Cars Dieter Zetsche sits in the new Mercedes GLE Coupe during a preview event for the media, ahead of the 2015 North American International Auto Show (NAIAS) in Detroit, Michigan, January 11, 2015. (Photo by Mark Blinch/Reuters)

Ford Motor Co., Executive Chairman Bill Ford, left, and President and COO Mark Fields stand next to the new Ford GT during the North American International Auto Show, Monday, January 12, 2015 in Detroit. (Photo by Carlos Osorio/AP Photo)

The 2016 Chevrolet Volt hybrid is unveiled during the first press preview day of the North American International Auto Show in Detroit, Michigan January 12, 2014. (Photo by Rebecca Cook/Reuters)

The Chevrolet Bolt EV electric concept car is unveiled during the first press preview day of the North American International Auto Show in Detroit, Michigan January 12, 2014. (Photo by Rebecca Cook/Reuters)

The Chevrolet Bolt EV electric concept car is unveiled during the first press preview day of the North American International Auto Show in Detroit, Michigan January 12, 2014. (Photo by Rebecca Cook/Reuters)

The Chevrolet Bolt EV electric concept car is unveiled during the first press preview day of the North American International Auto Show in Detroit, Michigan January 12, 2015. (Photo by Rebecca Cook/Reuters)

The Chevrolet Bolt EV electric concept car is unveiled during the first press preview day of the North American International Auto Show in Detroit, Michigan January 12, 2015. (Photo by Rebecca Cook/Reuters)

The 2016 Chevrolet Volt hybrid is shown during the first press preview day of the North American International Auto Show in Detroit, Michigan January 12, 2015. (Photo by Rebecca Cook/Reuters)

The 2016 Nissan Titan pickup truck is unveiled at the first press preview day of the North American International Auto Show in Detroit, Michigan, January 12, 2015. (Photo by Mark Blinch/Reuters)

Nissan CEO Carlos Ghosn speaks next to the 2016 Nissan Titan pickup truck after it was unveiled at the first press preview day of the North American International Auto Show in Detroit, Michigan, January 12, 2015. (Photo by Mark Blinch/Reuters)

Members of the media surround the 2016 Nissan Titan pickup truck after it was unveiled at the first press preview day of the North American International Auto Show in Detroit, Michigan, January 12, 2015. (Photo by Mark Blinch/Reuters)

Interior view of the 2016 Nissan Titan pickup truck after it was unveiled at the first press preview day of the North American International Auto Show in Detroit, Michigan, January 12, 2015. (Photo by Mark Blinch/Reuters)

The 2015 Alfa Romeo 4C Spyder is displayed during the first press preview day of the North American International Auto Show in Detroit, Michigan January 12, 2015. (Photo by Rebecca Cook/Reuters)

A 2015 Alfa Romeo 4C (bottom) is displayed along with a 1967 Alfa Romeo 33 Stradale (top) during the first press preview day of the North American International Auto Show in Detroit, Michigan January 12, 2015. (Photo by Rebecca Cook/Reuters)

Rear view of the 2015 Alfa Romeo 4C Spyder as it is displayed during the first press preview day of the North American International Auto Show in Detroit, Michigan January 12, 2015. (Photo by Rebecca Cook/Reuters)

A 2015 Alfa Romeo 4C Spyder is shown under a 1967 Alfa Romeo 33 Stradale (top) and another 4C (middle) during the first press preview day of the North American International Auto Show in Detroit, Michigan January 12, 2015. (Photo by Rebecca Cook/Reuters)

Reid Bigland, President and CEO of Alfa Romeo North America, speaks next to a 2014 Alfa Romeo 4C (top) and a 2015 4C Spyder during the first press preview day of the North American International Auto Show in Detroit, Michigan January 12, 2015. (Photo by Rebecca Cook/Reuters)

Front quarter view of a Ford Raptor pickup truck as it is displayed during the first press preview day of the North American International Auto Show in Detroit, Michigan, January 12, 2015. (Photo by Mark Blinch/Reuters)

A Ford Raptor pickup truck is displayed during the first press preview day of the North American International Auto Show in Detroit, Michigan, January 12, 2015. (Photo by Mark Blinch/Reuters)

The Ford Mustang GT 350 R is displayed during the first press preview day of the North American International Auto Show in Detroit, Michigan, January 12, 2015. (Photo by Mark Blinch/Reuters)

Ford President of the Americas Joe Hinrichs speaks next to a Raptor pickup truck during the first press preview day of the North American International Auto Show in Detroit, Michigan, January 12, 2015. (Photo by Mark Blinch/Reuters)

A Ford Raptor pickup truck is displayed during the first press preview day of the North American International Auto Show in Detroit, Michigan, January 12, 2015. (Photo by Mark Blinch/Reuters)

Detail view of a wheel on the Volkswagen Cross Coupe GTE concept vehicle as it is displayed during the first press preview day of the North American International Auto Show in Detroit, Michigan, January 12, 2015. (Photo by Mark Blinch/Reuters)

The 2015 Acura NSX is displayed during the first press preview day of the North American International Auto Show in Detroit, Michigan, January 12, 2015. (Photo by Mark Blinch/Reuters)

The 2015 Acura NSX is displayed during the first press preview day of the North American International Auto Show in Detroit, Michigan, January 12, 2015. (Photo by Mark Blinch/Reuters)

View of the interior of the 2015 Acura NSX as it is displayed during the first press preview day of the North American International Auto Show in Detroit, Michigan, January 12, 2015. (Photo by Mark Blinch/Reuters)

The 2015 Acura NSX is displayed during the first press preview day of the North American International Auto Show in Detroit, Michigan, January 12, 2015. (Photo by Mark Blinch/Reuters)

Members of the media crowd around the 2015 Acura NSX as it is displayed during the first press preview day of the North American International Auto Show in Detroit, Michigan, January 12, 2015. (Photo by Mark Blinch/Reuters)

Members of the media look over a 2016 Toyota Tacoma pickup truck after it was unveiled during the first press preview day of the North American International Auto Show in Detroit, Michigan, January 12, 2015. (Photo by Mark Blinch/Reuters)

The 2016 Toyota Tacoma pickup truck is unveiled during the first press preview day of the North American International Auto Show in Detroit, Michigan, January 12, 2015. (Photo by Mark Blinch/Reuters)

The Hyundai Santa Cruz crossover concept truck is displayed during the first press preview day of the North American International Auto Show in Detroit, Michigan January 12, 2015. (Photo by Rebecca Cook/Reuters)

The Hyundai Santa Cruz crossover concept truck is displayed during the first press preview day of the North American International Auto Show in Detroit, Michigan January 12, 2015. (Photo by Rebecca Cook/Reuters)

The Hyundai Santa Cruz crossover concept truck is displayed during the first press preview day of the North American International Auto Show in Detroit, Michigan January 12, 2015. (Photo by Rebecca Cook/Reuters)

Front end detail of the Hyundai Santa Cruz crossover concept truck as it is displayed during the first press preview day of the North American International Auto Show in Detroit, Michigan January 12, 2015. (Photo by Rebecca Cook/Reuters)

A 2015 Bentley Mulsanne Speed is detailed while on display during the first press preview day of the North American International Auto Show in Detroit, Michigan January 12, 2015. (Photo by Rebecca Cook/Reuters)

The 2016 Volvo XC-90 hybrid plug-in is displayed during the first press preview day of the North American International Auto Show in Detroit, Michigan, January 12, 2015. (Photo by Mark Blinch/Reuters)

Front quarter view of the 2016 Volvo XC-90 hybrid plug-in as it is displayed during the first press preview day of the North American International Auto Show in Detroit, Michigan, January 12, 2015. (Photo by Mark Blinch/Reuters)

Detail view of the 2016 Volvo XC-90 hybrid plug-in port as the vehicle is displayed during the first press preview day of the North American International Auto Show in Detroit, Michigan, January 12, 2015. (Photo by Mark Blinch/Reuters)

Hakan Samuelsson, President & CEO, Volvo Car Group, speaks next to his company's XC-90 during the first press preview day of the North American International Auto Show in Detroit, Michigan, January 12, 2015. (Photo by Mark Blinch/Reuters)

Two models unveil the Chinese Guangzhou Automobile Group (GAC) GS4 during its world debut at the first press preview day of the North American International Auto Show in Detroit, Michigan January 12, 2015. (Photo by Rebecca Cook/Reuters)

Two models unveil the Chinese Guangzhou Automobile Group (GAC) GS4 during its world debut at the first press preview day of the North American International Auto Show in Detroit, Michigan January 12, 2015. (Photo by Rebecca Cook/Reuters)

CEO and founder of Local Motors John B. Rogers (at podium) speaks to the media as his company showcases the world's first 3-D printed car, the Strati, during the first press preview day of the North American International Auto Show (NAIAS) in Detroit, Michigan, January 12, 2015. (Photo by Mark Blinch/Reuters)

CEO and founder of Local Motors John B. Rogers (driving car) and Milt Peterson, of Peterson Companies, showcase the world's first 3-D printed car, the Strati, during the first press preview day of the North American International Auto Show (NAIAS) in Detroit, Michigan, January 12, 2015. (Photo by Mark Blinch/Reuters)

Acura introduces the new NSX at the North American International Auto Show (NAIAS) on January 12, 2015 in Detroit, Michigan. (Photo by Scott Olson/Getty Images)

The new General Motors Buick Avenir Concept vehicle is shown after it was revealed to the media on the eve of the 2015 North American International Auto Show January 11, 2015 in Detroit, Michigan. (Photo by Bill Pugliano/Getty Images)

The Buick Avenir concept is on display during media previews for the North American International Auto Show in Detroit Monday, January 12, 2015. (Photo by Paul Sancya/AP Photo)

Journalists surround the new Ford GT after it was unveiled at the North American International Auto Show, Monday, January 12, 2015 in Detroit. (Photo by Carlos Osorio/AP Photo)

The new Mercedes GLE Coupe SUV is unveiled at the North American International Auto Show, Monday, January 12, 2015, in Detroit. (Photo by Tony Ding/AP Photo)

Journalists photograph the interior of Volkswagen's new Cross Coupe GTI SUV that will come out in 2016 at North American International Auto Show on Monday, January 12, 2015 in Detroit. This is a Theta 360 photo. (Photo by Julian H. Gonzalez/Detroit Free Press/TNS)

The 2016 Nissan Titan is introduced to the media during the 2015 North American International Auto Show at Cobo Center on Monday, January 12, 2015 in Detroit. (Photo by Regina H. Boone/Detroit Free Press/TNS)

The Mercedes-Benz F 015 concept is introduced to the media during the 2015 North American International Auto Show at Cobo Center on Monday, January 12, 2015 in Detroit. (Photo by Ryan Garza/Detroit Free Press/TNS)