My mom couldn't. Dad bought her an S550 in the late 00's (a W221) and it had the COMAND sytem and she could not operate it. She was never very good at understanding the concept of a menu system where a button could have more than one function, so this was too much.
My sympathes lie entirely with her.
Techbros need to learn that people need to be able to work these systems; there is no point in being too clever by half and dazzling people with technology, if they don't understand it and are unable to use it.
Actually, this is a strong argument for diversity - and the input of different life experiences - at the design and engineering stage.
Moreover, if you (by that, I mean "one" as in "one spends") spend your life at school and in a cultural milieu, (as many girls and women do) being told (consciously and more subtly) that they are thick at tech, well, is it any surprise that many internalise this message, and believe that mastering this stuff is entirely beyond them?
Furthermore, if it doesn't work easily (remember that early Apple slogan "it just works"?) - if understanding how it works is too complicated - for those who are to use the system, then, that is a design fail, no matter how pretty it looks in the car.
No matter how many times I showed her how to change from Sirius to AM, she simply could not remember. Of course she was late 70's by this point.
Dad finally gave up and downgraded her to an E550 which still had physical buttons.
But, why does it have to be that complicated?
Switching on - or, being able to operate - a car radio shouldn't require a postgraduate degree (and I have postgraduate degrees, as does my brother, yet that damned touchscreen defeated us both).
Being 70+ has nothing to do with it.
Decent Brother & I were - and are still - (a few) decades away from 70+ and we were both incredibly frustrated, dealing with this.