In the context of high energy use and greenhouse gas emissions from road passenger transport, the prospects of market diffusion of new car technologies is at present time uncertain. For instance, the impact of current oil prices on the market uptake of electric vehicles is yet to be seen. Systems thinking and scenario analysis are useful to explore possible future outcomes. This paper focuses on car technologies scenarios for the Chinese, German and US markets until 2030. The technologies investigated are: gasoline, diesel, flexi-fuel, liquefied petroleum gas, natural gas, hybrid, plug-in hybrid, battery electric and fuel cell vehicles. Based on the System Dynamics approach, a model integrating discrete choice and accounting frameworks is developed. The developed System Dynamics model is applied to examine alternative policies and to estimate energy use and emissions in each of the markets under various scenarios. The model results illustrate the importance of taking indirect emissions into account. In conclusion, simulated policies sensibly alter car technology uptake and have an impact on the environment. Finally, the ideas of feedback process and expansion of model boundaries are considered to be crucial in modeling such a complex and uncertain system.