Check out audiobooks from the library before your road trip
Moxie's suggestion for road trip relief:
Travel hack (not nearly as creative as the one from the guy telling people how to make their own CDs for road trips): Most public libraries have a decent selection of books on CD. Borrow a couple children's books and listen to them as you drive on long car trips. This can reduce the fighting over who gets to choose the music, and make everyone enjoy the car time a little more. Last year we listened to Carl Hiaasen's Hoot while we drove all over Minnesota.