A Google search turned up one interesting result. One mom made something similar to the Munchie Mug by stretching a couple of pieces of stretchy fabric over the top of a cup and securing it with a rubber band. Great idea, but I saw two problems with it: 1) Jem would figure out how to remove that fabric and rubber band in two seconds flat and 2) the rubber band would then become a choking hazard. It did give me a great idea though. I thought I could use the same kind of method with a mason jar ring instead of a rubber band. Unfortunately I couldn't find any plastic containers around the house that fit my mason jar rings, and I didn't think it would be a good idea to hand my 14 month old an actual mason jar.
The only other things I had that might work were wide mouth baby bottles. We use Pura stainless steel bottles, but since we only have three and we're still using them to transition Jem to a sippy (the nipples can be interchanged with Avent sippy spouts) I decided instead to use the lonely plastic Avent Magic sippy cup someone gave us that we never use. I should have Freecycled it away by now, but since I didn't I figured I'd give it a shot!
My biggest concern was that the hole at the top might be too small for Jem to fit his hand into, and it is. Luckily he's a pretty smart little kid and figured out how to get the Cheerios out by tipping the cup and using just his second and third fingers to fish them out. I figure anything that forces him to use his brain and develop fine motor skills is a plus! So overall, it's been a big success and a big hit!
This is how I did it:
~ 1 small wide mouth bottle, plastic or stainless steel (can also use a plastic container with a mason jar ring if you can find one that works!)
~ 2 pieces of stretchy fabric big enough to fit over the mouth of the bottle (I cut up an old bathing suit top that didn't have a bottom)
~ A knife or pair of scissors
1) Fill the cup with dry snack pieces. Jem loves his Cheerios (well, we buy an organic version).
2) Using the knife or scissors, cut a small slit into the center of each piece of fabric.
3) Place one fabric piece over the other with the slits criss-crossing and place over the mouth of the cup.
4) Screw the ring back onto the bottle over the fabric, being very careful not to overstretch the fabric or the slits will become too wide and the snack pieces will fall out when tipped. You might have to play with this a little.
You now have your very own Snack-Trap-Catcher-Munchie-Mug-thingamajig! Hold it upside down to make sure the pieces don't fall out. Some will likely fall out of you give it a good shake, which is okay. This is just to contain the worst of the messes!
Give it to your child and see what he or she does with it. It might take a couple of minutes for them to figure it out. You may have to help them. Once they get the hang of it, hopefully your car rides and snack times will be just a little more peaceful too! :-)