Stop already...
Back in the 70s-early 80s cars that were built in America were eaten by road salt in 3-5 years. Main Bearings in Vehicles were lucky to last past 50-60,000 miles as the prices continued to out pace the wages of Middle America people started looking for options.. That is what drove people to look elsewhere along with increasing fuel costs...
Recently GM just had to admit they had a faulty ignition switch problem they knew about for 10 years in some cases causing death. I have a buddy that had to have the Cam replaced in his Chevy Truck because of weak steel causing the lobes to wear.
Fact is GM,Ford and Chrysler all waited almost too long to get with the Quality Control Program and inprove their Products. It caused Chrysler and GM to need bailouts to keep them from shuttering.
That wasn’t any overseas conspiracy. That was Corporate Decisions for short term gain versus long term planning.
Part of what you say may be true, however, my personal experience denies your assertions.
I do not live in the north or other region that has to contend with “road salt” but DO live in the state of Florida and on the beach where Sea Salt is a big problem for some people. I never had a problem with rust and still don’t though my Buick is a 2003 Century. I drove Oldsmobiles until they stopped making them. Now I drive Buicks. NEVER had a car repainted. My son, during the period you mention, drove a Chevy 4 W.D. pickup well over 360,000 miles. He had another with well over 300,000 miles and has just bought another Chevy 4WD last week. As a well driller, pulling drilling rigs is tough on a truck, and the terrain is anything but easy, but never caused him a problem with a Chevy. During that period he had friends and competitors driving Toyotas and other foreign marks changing their trucks constantly. He just laughed at them.