The Nissan Leaf electric vehicle on display at the North American International Auto Show, Detroit, Michigan, USA, North America

The 1952 Mercedes 300SL race car on display at the North American International Auto Show, Detroit, Michigan, USA, North America

The Chevrolet Volt electric car on display at the North American International Auto Show, Detroit, Michigan, USA, North America

The 2013 Ford Focus ST on display at the North American International Auto Show, Detroit, Michigan, USA, North America

The Honda Personal-Neo Urban Transport, P-NUT, on display at the North American International Auto Show, Detroit, Michigan, USA, North America

The BMW i8 concept plug-in hybrid on display at the North American International Auto Show, Detroit, Michigan, USA, North America

The Smart For-us concept electric pickup truck on display at the North American International Auto Show, Detroit, Michigan, USA, North America

The Volkswagen e-Bugster concept electric car on display at the North American International Auto Show, Detroit, Michigan, USA, North America

The Hyundai Elantra plug-in electric car, developed for future production, on display at the North American International Auto Show, Detroit, Michigan, USA, North America

The 2013 Ford C-Max Energi plug-in hybrid electric car on display at North American International Auto Show, Detroit, Michigan, USA, North America

Two Chevrolet electric cars on display at the North American International Auto Show; the yellow EN-V pod-like car is a concept; the red Volt is in production, Detroit, Michigan, USA, North America

The 2012 Scion IQ on display at the North American International Auto Show, Detroit, Michigan, USA, North America