In fairness to everyone, in my opinion, which is not a claim to know anything or everything (
)........
I think we have two basic design criteria for American cars.
#1 is to be an American car as a completely different and unique vehicle from European cars. Large looking, large feeling, roomy and some level of posh interior and a cushy, floaty ride. The control and handling on this type American car is light years ahead of where they were just a decade ago. They are built specifically for those who DON'T WANT and DON'T LIKE a European car. Unfortunately, as more Americans drive and ride in todays top quality European cars, this market has shrunk and now 4.00 plus gasoline may have finished it.
#2 is to compete directly with European cars and here is where they've done too little for too long. I also believe, to a large degree, they have been trying to short convert designers of #1 into overnight designers of #2 and it has not worked. It may also be they have nothing to really offer European designers for attractive employment, or there is some other reason they are not getting top flight European designers.
As a qualifyer, I consider most Asian cars to be also a European STYLE car.
I believe, also, unions are a factor, but the union worker will do an equally good or bad job on whatever has been designed, considering how they are treated by a particular plant's management. Honda builds fine cars at Marysville, Ohio with UAW workers. Honda's blessing is they don't have a one hundred year history of conflict with the union.
All this being said, at one time the Big Three had every ability to make a car Porsche could only dream of, but decided not to. Don't ask me why, it's insanity to
have ignored this market until they had no other choice but to go after it.
Now that they are going after it, they don't want to actually consider what it really is car buyers like us want.
Personally I'd try to start where Dr. Porsche started. I'd take a small bore 4 cylinder, manual transmission FWD unit and do a fairly high tech material 1750 lb. mid engine car without many bells and whistles. Keep it simple, straight forward, handle like a Lotus and get at least 50 MPG as a commuter. In fact, rather than claiming to out Porsche a Porsche, I'd start a new class of car and ask why Porsche hadn't done it. I'd make sports/commuter cars. What better way to get people in 50 MPG cars than to make them fun as hell to drive?