re: Auto parts
Nearly all auto parts are made by independent manufactory’s and provided to the auto makers these days. The only difference from aftermarket parts and original equipment manufactory (OEM) is the logo in most cases. Sure there are a few sub-quality after market parts, but you can find after market parts that are made from the same people who provided the auto manufactures with the same parts, only they don’t have the logo on them.
When I was restoring my 82 Corvette I found that a lot of private companies had bought the dies and tooling from GM so they could build OEM parts as they are preferred for restoring a vehicle.
I suspect if the big three go down this will continue so we will be able to keep our cars rolling down the road.