I would think that a lighter skin would make for a lighter car which would improve fuel consumption.
GINA stands for “Geometry and Functions in ‘N’ Adaptations”, which basically means that designers from both BMW and BMW Group DesignworksUSA were allowed to throw out the rulebook. This is most evident in the GINA Light Visionary Model’s outer skin, which is made entirely out of textile fabric that’s pulled taut around a frame of metal and carbon fiber wires. The skeleton of the car is controlled by electro-hydraulic devices and can actually move and change shape beneath the fabric skin. For instance, the headlights of the concept can be exposed or hidden by the car’s skin just like blinking eyes, and the hood opens from the center as the fabric parts to expose the engine. This idea extends to the interior, where BMW designers have made visible only those instruments that are required at a certain time, while the rest of the time the same fabric interior “blinks” them out of view.