For the benefit of a sustainable global development of energy consumption and its climatic impact the per-capita energy consumption in industrialised countries such as Switzerland shall be reduced, with the vision of not exceeding the actual global average of 2000 Watts. Reaching this goal affects all sectors, particularly the building and the transportation sector, as a main originator of CO2-emissions in Switzerland. In this sector, the most important effect is achieved by not only reducing consumption but also advancing alternative drive train technologies. The market penetration of these new technologies is to be modeled in order to learn more about the fundamental processes and derive strategies contributing to their successful introduction. An existing system dynamics model for the market penetration of passenger cars with new drive train technologies, focusing on natural gas vehicles (NGVs) as a first alternative to conventional gasoline and diesel cars, forms the basis for further work and is shortly described. Possible extensions, mainly in the customer sector, are discussed, as well as the introduction of different model layers for additional drive train technologies competing with each other. Finally a game theoretical approach to simulate the exogenous stakeholders shall link them closer to the system dynamics model.