KAWASAKI, Japan (AP) _ Hiroshi Sato had just finished his day shift plus two hours of overtime at the sprawling Mitsubishi Motors auto plant in this bleak industrial city south of Tokyo. There was a cold hike to the station and an hour on the train between him and dinner with his family.

''What do I think of America?'' he said, straining his voice over the blare of a siren beckoning workers to the night shift. ''That must be the good life.''

Sato and his co-workers, like many Japanese, say they don't hold a grudge against American workers or products and take exception to recent comments by Japanese politicians disparaging American work habits.

In fact, many Japanese auto workers are unhappy about their own working conditions and are fed up with carrying a good part of the Japanese economic miracle on their backs. About two-thirds of Japan's $39 billion trade surplus with the United States comes from sales of cars and auto parts.

''Lots of us Japanese would love to live American lifestyles - take more vacation, spend more time with our families, not work as much overtime - but we can't,'' said Satoru Sasaki, a parts inspector at the Mitsubishi plant.

''Take a look around,'' said Akikazu Kashiwagi. ''Japan is supposed to be a great economic power, but we have to live in small houses far from the factory, we always have overtime, overtime, and hardly any vacation. This is really a poor country in some ways.''

Japanese auto makers are aware of these complaints, and are starting to address them. Toyota recently annouced a plan to begin to improve its working conditions and lower the work week from 45 hours to 40 hours by fiscal 1993.

Few auto workers have the time or interest to follow the war of words building across the Pacific Ocean - Americans blaming their economic woes on unfair trade practices in Japan, and Japanese officials saying U.S. problems are homegrown.

''Japanese politicians have a pretty strange way of thinking,'' said Tetsuo Endo, a manager at the Mitsubishi plant. ''We certainly don't think of Americans as being lazy.''

Endo was referring to comments two weeks ago by Lower House Speaker Yoshio Sakurauchi, who said American workers are lazy and sometimes illiterate. On Monday, Prime Minister Kiichi Miyazawa touched off another uproar in the United States when he said the work ethic of Americans was on the decline.

Both leaders said they were misunderstood and did not mean to disparage American workers. They said their comments were really aimed at problems created by American management practices, which many Japanese leaders contend is the real culprit in U.S. economic troubles.