Sustainable development refers to development that meets the needs of the present without compromising the ability of future generations to meet their own needs. It takes into consideration the economic, social and environmental aspects of development. Investing in renewable energy sources is the main element in sustainable development. It reduces the dependence on fossil fuels and decreases greenhouse gas emissions, thus reducing climate change's impact. Hence, promoting sustainable development through educating the public is essential. With 90 per cent of its vehicles being fossil-fueled, Malaysia needs to catch up in its aspiration to adopt green transportation. This study looks into the mediating effect of environmental concern on the relationship between social influence and prices of the green car on the post-purchase satisfaction of green car owners in Malaysia. Education and awareness campaigns play a significant role in promoting sustainable development. The domain of study is marketing, with post-purchase satisfaction as the central idea. It is a quantitative study based on the deductive research approach. This study chose the Theory of Planned Behaviour as its underpinning theory. The sampling technique adopted would be stratified random sampling via a self-constructed questionnaire. It will collect data from 384 respondents using a questionnaire and analyse it statistically using the SPSS and SmartPLS statistical tools.