My thoughts/observations on: "...do you notice the same waning interest in cars with the younger generation?"
Answer = yes. In no particular order, younger generations in general:
(1) Have other priorities (e.g. are more interested in having an "i" something versus a car (e.g. iPhone, iPad, video games))
(2) Have never changed their oil, let alone pulled a head off a motor. Most probably don't know the difference between a coil spring and leaf spring. This could be a result of their fathers having less interest in cars, and the pleasure/joy of interest in cars started to fade there.
(3) Work less (if at all) and depend on their parents financially far more than my generation did (BTW: I am 45 so its not sooooo long ago). My first job: I was 10 and guess what that was? Yes, washing cars! How did you guess? (grin). Granted I didn't wash 10 cars a week, but I washed a few and did it the very best I could, got paid nominally for it. My grandfather taught me and his car was thus maintained to the tee, gratis of course. I also cut lawns and shoveled snow. By the age of 13, I had $ 4,000 saved in my bank passbook. At the age of 16, I started by own DJ business which allowed me to pay for college, a car, gas and insurance. Very few kids these days work, even at high school and college ages. Some don't want to, and others are coddled in a bubble by their parents doing them a great disservice in the end. My Dad always said "Hard work beats talent when talent doesn't work hard."
(4) Work ethic. Owning a car takes physical effort, and my first hand experience with younger kids these days is most shy away from labor as if it's the plague. Case in point: A few years ago I voluntarily ran a concert series in my town; 8 events per summer. Each event included staging, audio, lighting, green room, food concessions etc. One day a father from town said "My son is interested in helping". I said, "...WOW that's great!!! He can start next Sunday. Ask him to be here at 9 am." The father IMMEDIATELY questioned why his son had to be at the concert location at 9 am for a 6 pm concert. I politely told him "...the speakers, instruments and lights don't set themselves up." He got the point and his son appeared the following Sunday at 9 am very begrudgingly. By noon - just 3 hours later - the kid (approx. 17-18 years old, 200 pounds) was NO WHERE to be found. After unloading the truck, he left out of sheer exhaustion. He wanted no part of the physical labor of moving 300 pound amp racks and speakers.
Then fast forward to now: A Co-worker in the office asked if I could train his son on car detailing. I was THRILLED someone of the younger generation was interested, and gladly invited him to my house that Saturday to detail a neighbor's car. The young man (approx. 24-25) asked how many hours it would take. I told him "I can't be sure but we should plan on 6-7 hours for a full detail noting we'll be going slower as you will have questions." Saturday came around and needless to say he was a no show. Monday morning I asked the Dad where his son was, and he said "...he didn't think it was going to be that much effort. He figured an hour or two at the most."
(5) Use Uber and other car services.
(6) Interest in cars is often a social thing, shared among people with the same passion just as we Detailers do. As much "social" as kids these days are exposed to (e.g. Facebook, Instagram, etc.) I find very few are able to interact face to face with others in person - which is what passionate car ownership leads to (car shows, working in garages with friends etc.)
(7) Kids these days want immediate satisfaction and owning a car isn't always that way. You save up, your repair parts, you replace parts etc. This all takes time and patience.
Of course this does not apply to all who make up the younger generation.
ScottH