Chinese firms have become global leaders in the electrification, networking and intelligentization of vehicles. They are globally dominant in minerals extraction and processing and battery production for electric vehicles (EVs) and are becoming internationally competitive in the enabling microelectronics, components and systems. This report covers the role of Chinese firms in Southeast Asia across five segments of the EV supply chain, namely minerals extraction and processing; battery manufacturing, energy storage and charging; original equipment manufacturer (OEM) production of complete vehicles; microelectronics design and manufacturing; and research and development activities. The report focuses on Indonesia, Thailand, Malaysia, Singapore and Vietnam. These are the five ASEAN economies where activities relevant to EV production are concentrated and where Chinese firms are involved in the supply chain. The report concludes with policy considerations for ASEAN governments. EVs and connected vehicles have become a new front in the technology contest and political tensions between China and the US, with other big players like the European Union now also moving towards measures to shield their automotive sector markets and companies. As 'technology-taker' economies at the forefront of climate change, the nations of Southeast Asia have much at stake in informed choices about this supply chain. They can benefit from participation in the evolving automotive sector without committing to one side, despite continued escalation in the global technology and trade war.