I don't think the bottom's gonna fall out any time soon.
Couple months ago, a couple kids on bikes drew up near where I was getting out of my '68 Road Runner and said "cool car!"
Local yearly car show, where we get 500-600 cars, has people of all ages taking it in; the younger folks tend to bring projects, and ask questions.
The majority are Boomers (as am I) but the kids here show respect and are often curious about the Model Ts & such.
Local Cars & Coffee sees pretty much everything from wealthy guys with Ford GTs to youngsters with pick-ups & Chevelles & some import stuff.
Best thing is to get the stuff out and be friendly, not gouge people on parts, be helpful, and share our enthusiasm.