trouble with snacks...help!

readers, i need you help.  jack's new routine on the way home each day is to have a snack in the car.  he eats a big, nutritious snack right after his nap before i pick him up, so this car snack is purely for entertainment.  i pack it in the morning and trust him to hold it and feed himself all while sitting in his carseat in the backseat of the car.  i try to find things that don't need to be kept cold and that won't stain ifwhen dropped on the seats.  and, i would like to keep the snacks somewhat healthy, but i am running out of ideas.  jack is not eating nuts yet, so we don't have that option.  what do you suggest?  all snack ideas welcome...don't worry if they don't seem like "kid" snack ideas...jack sometimes eats dried seaweed for snack time at home (i won't let him eat it in the car because it would soon smell like a fishing boat)- my child has an amazing palate!