Only makes sense to manufacture your vehiles in/near the customers. Political issues are much less, import duties make you more competitive and you may better understand your market. Most new auto makers consider the cultural differences between different regions. US, Middle Eastern, Asian, developing countries etc, all benefit from making cars for their regional markets. Tesla's plan of continous improvement will give them a leg up on their competition. OTA updates and two way communications with the end user gives them a treasure trove of continous feedback on how their vehicles are used, and what changes they may be able to make to gain additional customers. Asia has much lower labor rates and overhead. Land is cheaper, environmental burdens less, and fewer governmental and labor regulations allow for a more effecient operation. Tesla wants to thrive in a world wide economy.