Roadtrip with a couple of friends many years ago, we actually brought a real book and took turns reading out loud. Sounds strange perhaps, but was really nice! We read Alice in Wonderland, which all of us hadn't read in many many years.

Another roadtrip with BF just last year, we had an mp3 cd with the complete Beatles collection. The cd player in the car for some reason organized the songs alphabetically. Was great for the first couple of hours, but after 6 hours of non-stop beatles I was about ready to jump out of the car and we had only reached N in the alphabet! I haven't played that cd since...