Hot wheels at the Frankfurt Auto Show

A Friend Me concept car of Nissan is displayed during the media day of the IAA international motor show in Frankfurt, Germany, on Sept. 11, 2013.

Audi Nanuk Quattro

The new Audi Nanuk Quattro is presented during a preview by the Volkswagen Group prior to the 65th Frankfurt Auto Show in Frankfurt, Germany, on Sept. 9, 2013. More than 1,000 exhibitors will show their products to the public from Sept. 12 through Sept. 22, 2013.

Audi Nanuk Quattro

The new Audi Nanuk Quattro is presented during a preview of the Volkswagen Group prior to the 65th Frankfurt Auto Show in Frankfurt, Germany, on Sept. 9, 2013.

Audi Nanuk Quattro

An Audi Nanuk Quattro concept car is presented at the IAA (Internationale Automobil Ausstellung) international motor show in Frankfurt, Germany, on Sept. 10, 2013.

Audi Nanuk Quattro

A hostess stands next to an Audi Nanuk Quattro during the first press day of the 65th Frankfurt Auto Show in Frankfurt, Germany, on Sept. 10, 2013.

AP Photo/Frank Augstein

An Audi Nanuk Quattro concept car is presented at the international motor show in Frankfurt, Germany, on Sept. 10, 2013.

Maserati Ghibli

A Maserati Ghibli is pictured at the Frankfurt Auto Show in Frankfurt, Germany, on Sept. 11, 2013.

Lexus LF-NX

The Lexus LF-NX concept car is presented during the second press day of the 65th Frankfurt Auto Show in Frankfurt, Germany, on Sept. 11, 2013.

Jean Bugatti

The new Jean Bugatti is on display during the second press day of the 65th Frankfurt Auto Show in Frankfurt, Germany, on Sept. 11, 2013.

Porsche 918 Spyder

Matthias Mueller, member of the board of directors for strategy of Porsche Automobil Holding SE and CEO of Porsche AG, presents the new 918 Spyder during a press conference on Sept. 10, 2013, at the international motor show in Frankfurt, Germany.

Porsche 918 Spyder

Matthias Mueller, member of the board of directors for strategy of Porsche Automobil Holding SE and CEO of Porsche AG, presents the new 918 Spyder during a press conference on Sept. 10, 2013, at the international motor show in Frankfurt, Germany.

Peugeot Onyx

The Peugeot Onyx concept car is on display during the second press day of the 65th Frankfurt Auto Show in Frankfurt, Germany, on Sept. 11, 2013.

Jaguar C-X 17

Jaguar's chief designer Ian Callum presents the C-X 17 crossover concept on Sept. 9, 2013, in Frankfurt, Germany.

Jaguar C-X 17

A Jaguar C-X 17 is presented during the first press day of the 65th Frankfurt Auto Show in Frankfurt, Germany, on Sept. 10, 2013.

Aston Martin 100

The Aston Martin 100 is presented during the second press day of the 65th Frankfurt Auto Show in Frankfurt, Germany, on Sept. 11, 2013.

Alfa Romeo 4 C

A hostess stands next to a Alfa Romeo 4 C during the first press day of the 65th Frankfurt Auto Show in Frankfurt, Germany, on Sept. 10, 2013.

Audi Quattro Sport

An Audi Quattro Sport concept hybrid car is presented during the media day of the international motor show in Frankfurt, Germany, on Sept. 10, 2013.

Audi Quattro Sport

An Audi Quattro Sport concept hybrid car is presented during the media day of the IAA (Internationale Automobil Ausstellung) international motor show in Frankfurt, Germany, on Sept. 10, 2013.

Audi Quattro Sport

An Audi Quattro Sport concept hybrid car is presented during the media day of the IAA international motor show in Frankfurt, Germany, on Sept. 10, 2013.

Volvo Coupe

The new Volvo Coupe concept car is on display during the second press day of the 65th Frankfurt Auto Show in Frankfurt, Germany, on Sept. 11, 2013.

Ferrari 458 Speciale

Ferrari President Luca di Montezemolo presents the new Ferrari 458 Speciale at the 65th Frankfurt Auto Show in Frankfurt, Germany, on Sept. 10, 2013.

Ferrari 458 Speciale

The new Ferrari 458 Speciale is seen at the 65th Frankfurt Auto Show in Frankfurt, Germany, on Sept. 10, 2013.

Opel Monza

Media surround a Opel Monza concept car during the first press day of the 65th Frankfurt Auto Show in Frankfurt, Germany, on Sept. 10, 2013.

Opel Monza

Opel CEO Karl-Thomas Neumann sits in a Opel Monza concept at the 65th Frankfurt Auto Show in Frankfurt, Germany, on Sept. 10, 2013.

Opel Monza

Mark Adams, vice president of General Motors Europe, presents the new Opel Monza Concept at the IAA auto show in Frankfurt, Germany, on Sept. 9, 2013.

Renault Dezir

A Renault Dezir concept car is displayed at the Frankfurt Auto Show in Frankfurt, Germany, on Sept. 10, 2013.

Citroen c-elysee WTCC

A Citroen c-elysee WTCC car is pictured during the media day of the IAA international motor show in Frankfurt, Germany, on Sept. 10, 2013.

Maserati Quattroporte Ermenegildo Zegna

A model stands beside the Maserati Quattroporte Ermenegildo Zegna at the IAA International Automobile Exhibition on Sept. 10, 2013 in Frankfurt, Germany.

Volkswagen e-up!

The Volkswagen e-up! rolls onto the stage during the first press day of the 65th Frankfurt Auto Show in Frankfurt, Germany, on Sept. 10, 2013.

Renault Twizy Sport F1

A Renault Twizy Sport F1 is on display during the second press day of the 65th Frankfurt Auto Show in Frankfurt, Germany, on Sept. 11, 2013.

Ford Vignale

The new Ford Vignale is on display on the first press day of the Frankfurt Auto Show in Frankfurt, Germany, on Sept. 10, 2013.

BMW i8

A BMW i8 plug-in hybrid sports car is displayed during its premiere at the first press day of the 65th Frankfurt Auto Show in Frankfurt, Germany, on Sept. 10, 2013.

BMW i3

The new BMW i3 electric car is presented during the first press day of the 65th Frankfurt Auto Show in Frankfurt, Germany, on Sept. 10, 2013.

BMW i3

The new BMW i3 with electric drive is presented at the IAA international automobile show on Sept. 10, 2013, in Frankfurt, Germany.

Smart four joy

The new Smart four joy is presented at the Mercedes booth during the IAA international auto show in Frankfurt, Germany, on Sept. 9, 2013.

Infiniti Q30

The new Infiniti Q30 concept car is presented at the IAA International Automobile Exhibition on Sept. 10, 2013 in Frankfurt, Germany.

Infinity Q 50

An Infinity Q 50 is pictured during the first press day of the 65th Frankfurt Auto Show in Frankfurt, Germany, on Sept. 10, 2013.

Fiat Panda

A hostess stands next to a Fiat Panda during the first press day of the 65th Frankfurt Auto Show in Frankfurt, Germany, on Sept. 10, 2013.

Peugeot 308

A photographer takes a picture of a Peugeot 308 hatchback during the first press day of the 65th Frankfurt Auto Show in Frankfurt, Germany, on Sept. 10, 2013.

Toyota Yaris Hybrid R

The Toyota Yaris Hybrid R concept car is presented during the first press day of the 65th Frankfurt Auto Show in Frankfurt, Germany, on Sept. 10, 2013.

Dacia Duster

The Dacia Duster is presented during the second press day of the 65th Frankfurt Auto Show in Frankfurt, Germany, on Sept. 11, 2013.

Mercedes S-Class Coupe

The Mercedes S-Class Coupe concept is on display during the first press day of the 65th Frankfurt Auto Show in Frankfurt, Germany, on Sept. 10, 2013.

Mercedes S-Class Coupe

Daimler CEO Dieter Zetsche gives thumb-up as he stands beside a Mercedes S-Class Coupe concept during the first press day of the 65th Frankfurt Auto Show in Frankfurt, Germany, on Sept. 10, 2013.

Mercedes S 500 plug-in hybrid

The new Mercedes S 500 plug-in hybrid is presented during the first press day of the 65th Frankfurt Auto Show in Frankfurt, Germany, on Sept. 10, 2013.

Bentley GT V8S

Wolfgang Schreiber, CEO of Bentley Motors, presents the new Bentley GT V8S during a preview by the Volkswagen Group prior to the 65th Frankfurt Auto Show in Frankfurt, Germany, on Sept. 9, 2013.

Citroen Cactus

The new Citroen Cactus concept car is presented during the media day of the IAA international motor show in Frankfurt, Germany, on Sept. 10, 2013.

Opel Adam

An Opel Adam car is seen at the IAA international motor show in Frankfurt, Germany, on Sept. 11, 2013.

Renault Spark SRT-01E

A Renault Spark SRT-01E FIA Formula E race car is presented at the booth of Michelin during the media day of the IAA international motor show in Frankfurt, Germany, on Sept. 10, 2013.