My issues are that it's not about how hard it is to teach, it's about the time/attention it takes to actually do the thing, and how predictable the path is. Because it's not even that short:

    - Identify if there's a dialog box showing.
      - If there is, dismiss it (sometimes tap outside it, sometimes click close, sometimes accept the prompt.
    - Then click the top level button, etc...

Once full self-driving is supported maybe it'll be less of an issue, but as long as I've got full control of the car, that represents at least 10 seconds of looking at the screen (hopefully broken up into chunks with glances at what's happening on the road).

There are so many buttons on my car that I don't know what they do. Although touch screen has its own issues, it's currently the only way to make the input UX updatable. Better speech recognition is clearly another option in the near future.

Are you implying that a 97 year old can't learn anymore? My 95 year old grandmother learned to use a Windows machine and an Android phone.

I have difficulty learning how to navigate a car's satellite radio touch screen. Things like understanding that Auto has AC on even though the AC light isn't on is hard to understand. Submenus and 6 pages of FM channels are also high in cognitive load. I'm 31, so frankly, no, age doesn't directly factor into it, but I've also been trying to teach students, coworkers, my parents, other adults, and grandparents how to use computer and their interfaces better for ~20 years.

There are a lot of tactile reasons that "stalks" work for lights and wipers, or that buttons press versus rotate. Or that things that do rotate click into place.

But if age does have a factor, vision, hearing, memory, and reaction time are all typically reduced.

Interestingly, I have 2 grandmothers at this age, both at extremely different levels of cognitive and physical ability.1 has an ipad and plays bridge on it, while the other hasn't been able to use a computer for a decade.

Not OP, but it's not just the ability but its also the willingness to learn new things.