sniplits for the car
Making the best use of the morning commute is a challenge, when kids are still sleepy and not ready for anything too challenging. One possibility is to play an audio snippet. To play in the car without wifi, save the file ahead of time by right-clicking on the link to the .mp3 and choosing 'Save link as...' or similar.
http://writersalmanac.publicradio.org/podcast/ has free podcasts about 'this day in history' with Garrison Keillor reading
Mark Twain snippets have been recorded and some of the funny bits are available here:
More podcasts: http://www.podcastawards.com/ has an education section.
Hardcore history gets into nitty gritty details, KidFriday.com is hip. All seem to have about 1-2 minutes up front of advertisements or chatter before the actual subject matter starts.
http://americanpublicmedia.publicradio.org/podcasts/ has public radio podcast links
http://audible.com is an Amazon store devoted to audio.