One answer to this conundrum lies in BYD’s ability to manufacture most of its components in-house. This allows the company to significantly reduce production costs and better control quality and the supply chain

Another important aspect is BYD’s ability to integrate complex components into simplified modules. A clear example of this is the E-Axle 8 in 1, which combines motor, inverter and reducer into a single unit

People also forget BYD Thailand factory is already operational and not all its cars are made in China.

https://www.reuters.com/business/autos-transportation/chinas-byd-opens-ev-factory-thailand-first-southeast-asia-2024-07-04/