I believe that the US auto manufacturers have suffered for decades now from the idiocy of letting the bean counters run them. Car companies need to be run by car folks and not accountants. The last car guy to run an American car company was Iacocca.
Example: How in the hell can the company that gave us the Corvette, new style Cadillacs and the GM trucks give us the Aztek?? Any moron from a high school mechanical design class would have laughed if shown a pre-production drawing of the Aztek. And to top that off, they quit production of the Camaro and Firebird, leaving the market wide open to the Mustang, which is selling like hot cakes by the way. Of course, Ford has their problem children too. Chrysler, being the smallest of the three, is more susceptible to the financial ups and downs of the qwerky auto market.
Oldsmobile had the hottest car for years, the Cutlass. As I recall the suddenly stopped production. They never recovered.