Another piece of the dog poop puzzle...

About a month ago I posted about the bags of dog poop I kept seeing on the back of a maroon Cadillac near my house, and I have exciting news! Just the other day I saw the dude who owns the car (I saw him sitting in there, remember?) walking a Large Dog, holding none other than a yellow bag of dog doo!! So it is the owner himself who puts the poop on his car. Now we know who, but the question of "Why??" still remains. Why wouldn't he just throw the poop away immediately? Does he throw it into his outside garbage can, or does he bring it somewhere else to throw it away? If he brings it somewhere else, does he put it in his car, possibly right there on the passenger seat beside him?