If it was a song by song shuffle so that that group's music came on for one song every 10 or 12 songs or so, I think it would be fine to leave it. But if it is a CD by CD shuffle so that you'd be listening to the group's entire CD before switching to another one? 30-45 minutes in a row of music you aren't enjoying would be a lot to take.
I am so with you there Outdoor Girl. I was once a passenger in a car on the A1(M) in the UK and it was a 5 hour ride, and it felt like most of it was taken up listening to the Best Of Jake Thackeray. For those of you who don't know him, he sang satirical songs, of dark humour, but without being able to actually sing, he sort of vocalised over a short range. One or two songs would have been fine, but not the whole lot, especailly as I was in the back of the car, and i couldn't hear everything clearly.
if it's a short journey, you should be able to put up with a song or two that you aren't keen on, but a long journey, the driver should be polite and ask if passenger are really into heavy metal or drum and bass or whatever before subjecting fellow travellers to such.