We buy cheese sticks for road travel. More expensive, but they don't stick together.
Will you be needing lunches and/or dinners in the car too? I usually make up rolls with tortillas, mayo, meat, and cheese. Sometimes I cut them into pinwheels. Other times I leave them as whole rolls. They are good and filling!
I make up little cups of yogurt. I don't like all the sugar in the premade kinds, so I buy the plain Greek yogurt and add honey or jam to it. I have individual serving size cups. Yum!
I also found my kids will eat pasta cold! I cook it and put it in individual size Ziploc bags. Hand it back with a fork and, voila! A meal!
Fresh fruit cut up and ready to eat in individual bags (easy to pass back). Blueberries, strawberries, watermelon, cantelopue, oranages.