A big memory of mine was driving my '72 Duster. I'd just bought Rod Stewart's "A Night on the Town" 8 track, and I was astonished to find a song about a gay guy. It was of course "The Killing of Georgie", and I must have played it back to back 20 times that night.
As bad as the 8 track sounded, most younger people don't understand what a revolution it was to control what music you listened to in your car. Very similar to the Walkman in terms of breakthroughs.
In the same vein, I'd be interested to know about streaming music. Are there large libraries of music one can subscribe to, and play what they want? Kind of like a giant Netflix for music? Or do you still have to purchase your own library. Obviously Hi Rez options are preferred.