US history is replete with examples of "boom towns" which eventually go bust or into "ghost towns."
Mining is just one example. Gold mining booms in California, Colorado, Silver mining booms in Colorado, Nevada, etc.
When the bonanza ended, folks left because necessity dictated they do so to survive.
Building huge volumes of vehicles was bound to "play out" eventually. The companies took far too long to improve both designs and quality.
The workers were not highly skilled, and the companies had financial incentives to take work to lower cost regions.
The other "rich vein" that played out was the overpaid union situation.
Once upon a time the human species was smart enough to move on. Get out of the way of disaster.
http://www.legendsofamerica.com/gt-hiddentales.htmlThem folks in Detroit could move to a present day boomtown, like those in oil production:
http://business.financialpost.com/2012/07/24/drilling-for-growth-the-u-s-s-top-ten-oil-boomtowns/?__lsa=58da-7452Then they would have to work. Detroit is a long term study in "survival of the fittest" for individuals and institutions.