The adoption of electric vehicles (EVs) in Thailand has been growing steadily. This research study investigated the Thai automotive industry cluster and completed an analysis of the EV transition to create a domestic industry, its social and environmental impacts, the laws supporting EVs, and consumer acceptance. The results of the study found that Thailand had 1.53 million EVs, accounting for 8.12% of all vehicles in 2023. This growing industry has a significant impact on Thailand’s GDP, highlighting the need for a strategic transition to support the development of the EV conversion industry. A particular focus is on the conversion of internal combustion engine vehicles that are over 10 years old. These debt-free vehicles, having simpler technology, present an ideal opportunity for modification as part of a broader strategy to prepare the domestic automotive sector for EV production and usage. A strong legal framework supports Thailand’s efforts by promoting the EV sector and EV conversion. The country is already a major automotive manufacturing hub, ranked 11th globally, with a robust automotive parts industry. Additionally, Thailand has a significant stock of older and classic cars, with 18.26% of its vehicles in 2023 being over 20 years old. The absence of laws restricting vehicle lifespan further facilitates the EV conversion process. Thailand’s legal measures also promote economic growth by supporting industries related to classic cars, with tax incentives designed to stimulate these sectors. The EV conversion business in Thailand attracted over USD 300 million in investment in 2023, with a survival rate of 97.33%, reflecting continuous year-on-year growth. These developments indicate that Thailand is well positioned to become a leading hub for EV conversion in Southeast Asia. If Thailand wants the EV conversion industry to grow without affecting stakeholders, those involved must consider the following issues or develop a transition strategy: (1) investment in the EV conversion industry; (2) environmental aspects of EV conversion; (3) laws related to EVs; and (4) consumers who are considering EV conversion. Countries with automotive industries similar to Thailand can consider using this model in their countries as well.