mhibdon, we just finished a 10 hour trip and our snack bag had almonds, pumpkin seeds, Goldfish crackers, grapes, cheese sticks (in a cooler) and individual sized baggies of cereal. I used the Kashi GoLean that has 13 g. of protein per serving, hoping that would offset the carbs somewhat. I don't try to go as low on carbs as some, though; I do best at 50-55%, so others may have some better ideas.
Good luck! Just remember, if it's not in the car, you can't eat it