Most of the factories were eventually just shut down and moved over seas to begin with. After free trade with countries like child , china that have no labor protections and extremely low wages were passed, The company's saw an easy way to get around unions. There was a reason why the vast majority of g m cars are produced outside of the us and have been for decades.It happened in a quick manner for the region. Those oil shocks in the 1970's were not good. The whole industry changed. And we could not make good smaller cars that were more reliable than Japanese ones. The pressure to purchase small cars was great and foreign cars were limited to 10% I think and that was gradually lifted. We ended up with clunkers like the Vega, Chevette, Citation, Pinto, Pacer and many others that were designed on the quick.