D.A.
We just took a 4000 mile round trip to NM from OR. The kids did great and my kids were 4.5 and 2. I made each a travel box. The older one is a girl and she had her own stationary, envelopes, stickers, tape, colored pencils, stencils, writing pen and pencil, index cards with hole punch and tied together with yarn for flashcards we made along the way. I started with some of her friends names and then some things we would be doing, but kept the words fairly simple. She now can write her friends names with ease. For the 2 year old boy, his box had a little racetrack painted on it and a couple of small matchbox cars. He had a roll of transparent tape (loved it), paper, envelopes, stickers, colored pencils. Both had sewing tape measures that retract and small magnifying glasses. Needless to say, the boxes were a huge hit. They often played with the cars and racetrack at night while camping. We also brought a dvd player and Signing Time dvds and Backyardigans. I know my hubby and I got tired of Backyardigans, but the kids never did.
I put the boxes away when we got home and will update them for the next long trip.
Oh, if you go to any National Parks, ask about the Junior Ranger program. At Aches Ntl. Park, both kids were able to participate, but at Redwood Ntl. Park, only my 4 yr old was allowed to do it.
We all had a blast. Shortly after that, we took a flight to CO. So, it is all do-able.
The travel kits and dvd player were the biggest hits. I had a travel box for myself with a couple of books for bed time and a couple of games that practiced colors, numbers and shapes. That way, both kids could play the game. The 2 year old needed a little help. One was a card game that had the Sesame Street characters and practiced colors, shapes, numbers, but I don't remember the name of it and it is put away in storage right now. It was kind of like Uno or Skip Bo, but for little kids.
There are lots of possibilities, but the kits were the biggest hit and enough stuff in them for hours of play, but small enough to fit on a lap in a car seat.
Have fun,
D.