I guess my question is, does she actively dislike the band, or did she just not get around to really listening to it? Because if it's the latter, I think you could just say, "Hey, I've got a CD by Band X here, do you want to give it a try?" And if she says yes, you go for it. And if halfway through she decides she doesn't like it, or she says no right away, you play something else you both like.
Although ultimately I think the driver does get to pick the music, playing something you KNOW your passenger specifically dislikes seems a little pointed to me, especially if it's an entire album/everything by a certain band, and not just one song flitting through the rotation. If there's the possibility of a happy medium I think that should be the goal. I think of the driver, if it's their own car, as being the host in some sense, and they should want to make their guest/passenger comfortable, within reason.