It’s even more rude in the car.
Depends on what else is going on. When you’ve got 10 people in the car, having one on Planet Zongo with headphones is okay.
When Anoreth went to D.C. with my mom last fall, Mom suggested she bring the CD player, so that Mom could listen to financial news and Anoreth could listen to Whatever.
I like to have conversations in the car, but there’s a place for the passenger(s) to space out and not need attention, especially in rough traffic.