Here’s what I’ve noticed from driving cross-country with kids.
Kids can sleep in any position.
Don’t give your son chocolate bars in the car. He will be quite proud of this.
Large numbers of books to read are always a good thing. Oh, and always wear cowboy boots on trips.
You can always entertain yourself by drumming on your backpack.
Oh, and pre-schoolers need to go potty at least once an hour, unless they’re asleep.