Mangement sets a cost per car that they want to maintain.
Union labor costs more, so that leaves less for parts.
In the cost cutting mentality of the Big 3 recently that means that parts keep getting cheaper.
I have 2 asian imports in my garage and one American made Ford (the Stang).
Six months ago I had three American made vehicles. Now it is down to one.
The quality of the Ford fit / finish / paint etc... is not even close to my imports. Anybody who goes and shops the asian imports against the Big 3, would quickly realize the quality difference.
I really want to buy American cars, but they have got to spend more money to do it right.
I just bought an SUV for my wife and one of the SUV's I checked out was the Lincoln Aviator. I was appaled to find my Stang radio under the slick stainless radio cover. Very Tacky and not acceptable at that price.