Within sustainable transportation systems, the adoption of electric vehicles (EVs) is considered as a potential solution to problems such as energy security, climate change, urban-air quality, and public health. This EV-adoption process is a complex system that considers the relationships between the dimensions of sustainability, car-ownership transition to EVs, market dynamics, and the government. Several models have been designed to address this system. However, these models have only partially developed these relationships because they did not consider all the components or relationships between the elements of this process. This article proposes a systemic approach based on previous models, which integrates all the components and relationships and incorporates the analysis of sustainability into the EV-adoption process. The system structure of this EV-adoption process is presented and discussed. This approach deepens the understanding of the synergies between market dynamics and sustainability, allowing to model the system more broadly. It can thus help in the sustainable and integrated evaluation of different policy scenarios, thereby contributing to a clearer understanding of the dynamic behavior and leverage points of the system.