when we go on long car trips, my family likes to play family games.
We play the alphabet game(where you have to find a word that begins with the letter on a sign, other car, etc. for example, the letter A might be on a sign for "Apple County." once one player uses the word "Apple" for the letter 'A,' noone else can use the word apple.) it gets really fun! you can divide the car into teams, or play with everyone on their own team.
We also play the liscense plate game, where we try to find a license plate from every state, and we play the flag game, where you divide the car into two teams, and whenever you see a flag, you scream flag! and your team gets a point(this can result in debates, and may annoy parents; my aunt has officially banned the flag game from her car because we get so competitive

).
that, and sleep. I can sleep just about anywhere, for an extended period of time.