I would just take whatever your kids normally eat unless it's ice cream or chocolate. When we were kids (6 of us, it was the 50s and 60s when road trips were the thing) Mama would pack grapes, carrots, celery and cheese in individual bags for each of us. When my son was little he was into cheese crackers and grapes so I'd just take a box of cheezits and a bag or grapes. He drank those capri sun things back then. Now, our "car food" is usually a couple of the pre-package protein snacks you can get at the store (you know the ones with cheese, nuts, meat and crackers) and a bag or something crunchy and something sweet. He loves sour gummy worms and hot tamales so a couple of boxes/bags of those. As an aside, the reason he loves gummy worms is because when he was little and used to whine I would tell tease him and tell him he ought to eat worms, bad Mama I know. We take bottled water because I don't drink soft drinks and other than my morning cup of coffee or a refreshing adult beverage, water is all I drink. He usually takes a coke for the morning and then it's water for him too.