IF YOU BUILD IT

When did re-assembling a car become "building" a car? That's what I want to know. I thought the people who built the car were the factory workers who started with a bucket of parts and turned it into a car. Restorers take the parts apart and put them back together. I think it would be more accurate to say that they are fixing a car than building a car. Yet "building" is the word you hear again and again these days. And don't even get me started on building an interior . . .