Japanese build cars in the USA . USA build cars in Mexico . Duh !
You really are ignorant of the history of US/Japanese trade relationships. You need to educate yourself about how Japan has used every trick in the book to protect its home markets while using every trick in the book to penetrate the US and other markets.
In the case of the US, it was easy since the US had a goal to rebuild Japan economically into a strong Cold War ally after WWII, so our markets were just opened to them and little was gotten in return.
The Asian model for growth is to protect their home markets and export as much as possible. Japan, South Korea and now China have been very successful using that model.