The absolutely disgraceful low point of the U.S. auto industry was the period of time between the end of the post-WW2 recovery and the rise of Asian auto manufacturers.
Go back and read about what was happening at "Big Three" plants in the U.S. from the late 1960s through the mid-1980s. The only thing that saved these companies was a swift kick in the ass from Japanese competitors like Toyota and Honda.
“The absolutely disgraceful low point of the U.S. auto industry was the period of time between the end of the post-WW2 recovery and the rise of Asian auto manufacturers. “
Are you talking about the quality levels of the cars, or the sales and profit levels of the companies ?
There were some stinkers during that timeframe to be sure, but a lot (not all) of that had to do with the heavy hand of government leaning on the industry during that era.
Don't forget, you had the National Traffic and Motor Vehicle Safety Act passed in 1966 largely in reaction to Nader's book, "Unsafe At Any Speed." Then in the early 70s, CAFE standards were enacted in the wake of the Arab oil embargo. It was a tough time for the auto industry. Certainly there were some very poor management decisions coupled with union apathy, kind of a perfect storm, that when considered holistically, would have made it surprising if the US auto industry had not produced the crappy cars it did at the time.