As for WTO cases involving the U.S. and Japan, we've won some and lost some. And the Japanese still haven't (re)opened their market to American beef, so you can easily say the record is mixed.
We lose most of the WTO lawsuits because they are reflexively anti-American. We are in a lose-lose position which is why I believe we need private trade agreements with individual countries which should be based on how open the foreign market is. Japan is using their advantage to price cars below the market in the US and making up for it in Japan where they face no competition. There is no reason for this situation to have gone on for over thirty years...something needs to be done about trade-fair trade.