Green cars are when it's environmental friendly and reuses things to make the car. Here are the examples of the green car's purpose:

1. Recycling Car parts
2. Biodegradable plastic/ green plastic
3. Product design ( this means designing the car, which is environment friendly like less noise & air pollution, less fuel consumption, use of recycled materials and design for service, and disassembly )
4. Green chemistry ( avoiding toxic, harmless solvents. )
5. Semiconductor, electronics (  more benign manufacturing projects. ) 
6. Lean manufacturing                                      Attention paid to waste generated along the way energy reduction in streamlined logistics.                                                                          Smart Car manufacturing and assembly plant in Hambach, France. Designed to minimize transportation, time and by-products.