* A streamlined shape with a narrow frontal area
* A smooth, contoured surface with few protrusions
* Active aerodynamics, such as a movable rear spoiler, that adjust to reduce drag
* Wheel covers that help to smooth airflow around the wheels
The Volkswagen XL1 is a plug-in hybrid electric car that can travel up to 31 miles on electric power alone. It has a top speed of 99 mph and a fuel economy of 261 mpg.