Abstract: The transport sector emits 18% of global CO₂. Industry and consumers must adopt green mobility to reduce emissions and climate change. This will help achieve sustainability by improving efficiency and reducing greenhouse gas emissions. Thus, smart electric vehicles (SEVs) have emerged. Digital twins concept and technology may help launch SEVs to the market by analysing and optimising supporting infrastructure. This work aims to fill in the gaps between different pieces of research by giving a full review from a technical and scientifically neutral point of view. The study looks at how digital twin technology can be used in smart car systems by looking at its promise and the hurdles faced. Based on a comprehensive literature survey, this is the first in-depth look at how digital twin technology can be used in smart electric cars. The review has been organised into specific areas of the smart vehicle system, such as drive train system battery management system, driver assistance system, vehicle health monitoring system, vehicle power electronics. This review goes into detail about each component of the car to provide an overall view of the smart vehicle system as a whole. This review makes it easier to understand how digital twin technology can be utilized into each area from a scientific point of view. Lastly, the work looks at the technological and economic impact of digital twin technology, which will make considerable changes in car manufacturing processes, as well as help address current obstacles in utilizing advanced technologies.