Detroit also engineered their cars to last about 2 yrs, so that people would have to get new ones.In the 1950s, Detroit was a worldwide hub of auto manufacturing, but the so-called Motor City began to decline after residents started to move and take their businesses, tax dollars with them.
Democrats & Unions take over, productive people leave.
Japan started to concentrate on quality in their manufacturing in the 50's.(Dr W Edward Demning found a receptive audience there in the 50's) They started making cars that would last over 150K miles. Soon more Americans were buying Japanese cars, they were cheaper and better engineered. That's what led to the decline of the American automobile industry, not unions. and with that decline, Detroit started to decline, just like any other city that lost its industrial base
honestly, you should really study history and economics, then you wouldn't sound like a complete idiot