Put a peice of duct tape on a wheel for every person in the car and make a bet that whoevers peice of duct tape is closest to the ground they get to get something at the gas station OR has to pay for half of the gas.
Get Spanish on tape and listen to it.
Play the ABC game:
Start at A and if you see a sign that has an a on it say: A tractor (or whatever the word is) and then go on to B and say: "B, Alabama" then go on to C and so on. The first person that gets done with Z wins! And then they get the satisfactory of saying i won all the way to your destination.
Listen to music and find a new radio station for every new area you are in.
Make a list of all the states and tally how many lisence plates you see of each one.