I was very curious about this, because of the pizza theories out there - I did try with several pizza pieces from different pizza shops - one was plain cheese, one had green peppers and pepperoni and one was a deluxe.
ALL THREE had the SAME EFFECT.
The green peppers wilted, eventually turned a dark grayish green color, all the crusts hardened, the pepperoni turned gray and hard, and THERE WAS NO SMELL, MOLD OR MAGGOTS.
I had them directly in the car - no bags, just one on the dash, one in the trunk and one on the backseat (an old car that was sitting outside.)
NOW - do you mean to TELL ME that KC used and made a pizza with fresh ingredients FROM SCRATCH, and did not order a pizza that came in the EMPTY box that was found?
If you don't believe us, try it yourself and you will see the light - there is NO DECOMP SMELL - not even a bad smell at ALL.