Homemade no-spill snack box
Remember the Snack Trap? Handy Sandy (I'm sure she'll just love that nickname) made her own:
If you have one of the smaller 8 oz empty formula tins (Similac tins work better than the Enfamil ones), you can adapt it easily to a "Surprise Snack Box." Take the plastic lid and cut a + in the center and shave the middle corners so they are rounded. A box cutter works great for this. Then use sand paper to smooth down the inner edges of the snack box so there are no sharp corners. This makes a good snack box. You can put in Cheerios, crackers, cookies and even gummy bears. Mix them up and close the cut-out-lid.
Since I introduced this to my son after his 1st birthday, he loves to peer into the box and stick his little hand in and see what treat he gets. In the beginning, he loved the ticklish feeling as he tried to dig in. The lid keeps the snacks and Cheerios safe from spilling out in the car, car seat, stroller, everywhere.... With the smaller opening than a normal snack cup, the little ones cannot get out more than a couple treats at a time. And what they get is almost always a surprise and will keep them busy in the car. When they are down and toss the box away, not much is likely to spill out. We never leave home without one - if we forget to take one, there is one in the car that we just fill up with goldfish crackers or peanut-butter-sandwich crackers at the nearest grocery/snack stand. Stick on some stickers and your kid will cling onto it for dear life anywhere you go.