None of these decreases will make much of a dent in the U.S.-Japan trade deficit. Japan pays a paltry 2.5% on auto and auto part imports in the United States, significantly less than beef and pork will be charged by Japan in 14 long years.
Japan has been allowed to keep its laws on cars and rice quotas in place without change. We will see how Japan treats Tesla as its sales of the Model 3 rise there. In the past Japan has imposed "non-tariff" barriers to many U.S. products.
Prime Minister Abe said President Trump agreed not to impose threatened "Section 232" tariffs on Japanese cars and parts on national security grounds. President Trump gave up a lot, and gained very little, through this new agreement.
The Japan-U.S. Trade agreement demonstrates that President Trump is not a very good negotiator. The trade agreement is partial at best, leaving major items to be negotiated in the future. Even if the President does not submit the treaty to Congress for its approval, Congress should enact legislation to either vote it up or down.