I wonder if it sits under the Makrolon roof or if it is something different? That car2go car direct from the factory is pretty cool too... 
car2go world first: dedicated car sharing vehicles straight from the factory
Another interesting feature is the 100 Watt solar panel on the roof, which is fully integrated into the onboard electronics. It will supply power to the telematics, charge the battery, and run the ventilation system when the car is parked in the sun. It will also allow the alternator to be decoupled while driving, which should reportedly reduce fuel consumption by up to 10 percent. Fuel will also be saved via an automatic start-stop system, which turns off the engine when the car isn’t moving.
car2go world first: dedicated car sharing vehicles straight from the factory

Another interesting feature is the 100 Watt solar panel on the roof, which is fully integrated into the onboard electronics. It will supply power to the telematics, charge the battery, and run the ventilation system when the car is parked in the sun. It will also allow the alternator to be decoupled while driving, which should reportedly reduce fuel consumption by up to 10 percent. Fuel will also be saved via an automatic start-stop system, which turns off the engine when the car isn’t moving.