J.M.
As many cd's you can borrow on one go from the library and a good DVD player and as many DVD's you can pack. Crayons and books and stickers and little toys will only go so far... they do help, but for that long, that's the way I'd go. And we commute 45 min each way everyweekday with my 4 1/2 and 2 1/2 yr olds in the back and two boxers in the passenger seat! :) And in a corolla to save on gas!!! :)