Another idea...lyrical science, science facts to song (pick the shorter ones,) they are funny!, Beethoven's Wig cd's are classical music with words, we learn alot of facts about composers or instruments with these,and they recognize the music if they hear it somewhere. Steve Green kids cd's are all Scripture....can you tell we like to learn to music. Geography cd's, we have learned the state capitals to song, we also do Bible verses and a catechism each week, plus classic poems, like Stopping by Woods on a Snowy Evening. Preamble to the Constitution is do-able, Pledge of Allegiance, Patriotic songs. The songs are the thing for us, they don't realize they are learning, and it keeps us happy in the car.