Car ride from Florida to Wisconsin was 21 hours in total spread out over 3 days. This was back in 2008 or something, so we didn't have any fancy tablets or satellite internet. I brought a blanket, pillow, and a portable DVD player. I borrpwed my uncles DVD collection and found the entire series of Evangelion within. Completed the series while on the road. Best long car ride ever.
Also, don't drink a lot of water. I happened to be seated next to a large case of water and just downed bottle after bottle due to boredom. Having to stop every 20 mins at a dirty gas station wasn't fun.