I worry about the same thing. Never discount the trades, someone willing to get their hands dirty and take some pride in their work will always be busy.
So many thoughts bouncing around my head about GM shutting down. So many factors leading up to this closure.
-Cost of living and debt levels have risen faster than wages, causing a push for higher wages. Used to be able to buy a house working a job with just a high school education, not so much these days. But at the same time we're responsible for the rising cost of living as our culture of consumerism constantly raises our living standards as we want more stuff and are encouraged to borrow more and more.
-Between the drive clean program and the 0% financing that was available during the economic crisis more people are driving new cars than ever. Leading to a slump in sales, since most people who were looking to replace a car have responded to incentives. Probably saw growth through the early millennium, with a plateau shortly after the recession. They managed to keep the plants running, but it's hurting them now.
-I feel that the manufacturers and the dealerships don't have the same goals in mind. Things such as selling cars at below purchase price in order to meet sales targets, so that the dealership receives the bonuses required in order be profitable. (Excellent podcast for any interested in dealership shenanigans -> https://www.thisamericanlife.org/513/129-cars .
-Cars are so complex and technologically advanced these days that prices become astronomical. Once again we're the source of our own problem, as consumers want gadgets and gizmos; and the environmental regulations require complicated control systems. Not saying that environmental regulations are necessarily bad in and of themselves, but can be taken past the point of common sense. I think that we're going to see a lot of cars scapped in the future because of electronics issues, costs a lot to buy the auto upfront and costs a lot to troubleshoot and repair the computerized modules when they break down.