I don't know if this has been said yet but eye masks and ear plugs for sleeping. My plan is also to bring a couple of thermoses (sp?) so when I do stop for caffeine I can get two tea's and just put one in the thermos for a bit later so we don't have to stop as often. Don't forget money for tolls, there are lots on the way down and back. We are also going to be putting some favorite shows or movies on our ipads to watch. But you can also put some books and games on there if you have one. This isn't stuff to pack in the car but things I am doing before we leave: call credit card company and let them know about your trip so they don't freeze it for weird charges, check the tire pressure to make sure we are getting the best gas mileage, and also give the car an oil change before leaving and probably one after we get home too.