There were MT plates issued during one of the wars that used compressed soy beans for plates to save metal for the war effort. Not many exist today because cows took a liking to them and nibbled them off the bumpers.
That's my honest recollection of the story someone told me. I saw one of those one time.
I didn't get much MT info from gramps during WWII being he was on a ship in the pacific, but he did say that metal was rationed during Korea, and that new plates were not replaced every year. "Every other year they issued a renewal with the windshield sticker".
The cows at the cabin in MT love to grab the hitch ball cap from my vehicle and suckle on it for a bit then spit it out.
Only thing I can think of is the road salt from winter still stuck on it and that they are going in for a taste.
