I listen to BBC Radio 4 quite a bit, but also CDs - usually stuff DH has left in the car as I'm rarely organised enough to sort out my own for a journey. I also listen to a German language learning course on CD while I'm driving, and songs in German to help DS learn too.
DS - June 2010
If the boys are I the car it's usually a cd, if its me by myself then its comedy or country radio.
Radio and the kids If there is a CD, it's typically a kids CD. They really like the "we sing" series -- they have a few of those.