When I'm in the car with my mom we never listen to my music because it grates on her nerves. I can relate because there's certain stores in the mall that I just avoid totally because they play to the "younger" generation and it gives me what I like to call bad music induced anxiety. There are some things like earrings or an office supply that I'd rather buy online just to avoid the music that is forced upon me at those stores.
Plus, I can listen to songs from my mom's generation and enjoy them no problem. My mom ended up riding in my car unexpectedly out in the middle of nowhere with no radio. I looked around for music that she'd enjoy and pulled out Songs for Christmas by Sufjan Stevens thinking that maybe I'd get in a few songs of something I liked. Surprisingly my mom liked most of it and could tolerate the rest; we ended up listening to all five discs. Thanks again Sufjan.