Foreign investment would be an economic boost for Mexico. The company has claimed that a plant there would create about 10,000 jobs. A Tesla competitor, BYD markets its Dolphin Mini model in Mexico for about 398,800 pesos—about $21,300 dollars—a little more than half the price of the cheapest Tesla model.
To counter those vague negative “maybes” of yours, I just want to point out that the EU, which have much more tight regulations on just about everything than the US, especially when it comes to consumer protection, allows the sale of BDY cars.
If a regulatory regime which is more strict when it comes to consumer protection than the US allows such cars to be sold, then claiming or implying that the reason for the US to block their sale there is that they might be dangerous is quite the flight of fantasy.