I’m 50 and I have a 1993 Miata, one of the ultra rare Red ones with a black top and black interior, so there are no parts out there that I can afford. Oh wait, I can buy whole cars for parts for dirt cheep based on my budget, combined with dead easy internet sourcing, 3D printing a part would not be my first choice today, mainly because it doesn’t have to be.
Now when I was 16 and driving a 1966 Plymouth Barracuda that was all kinds of brittle and broken and it could take months to find parts for it in that pre-internet diplopia called the 1980’s. The idea of the ability to print a part at home or at a local shop may have been my first choice. Then again, parts for a 1966 Plymouth aren’t all that hard to find today thanks to the internet.
In the end it comes down availability of usable parts, if I can source a new old stock or factory part that is serviceable and looks good, that will be my first choice, if I need an odd piece of trim that I can’t find but could 3D print and hand finish to look as good as the real thing I would do that with no problem with 3D printed. Also if the story of getting a part printed is better than the story of sourcing a factory part I’m totally in with 3D.