If you think building cars is unskilled labour I can only assume you've not owned anything newer than a Leyland P76, and managed to miss the whole "Japanese car makers eating the US and British industries" thing.

Auto workers have a skilled tradesman classification and other classifications and most aren't skilled tradesmen. They still perform pretty complex tasks. It's just a term, like how in insurance contracts you'll read "Act of God". That doesn't mean that State Farm is a theistic organization that believes that supernatural beings are imposing earthquakes upon us.