While I don't know where to find the plastic man ("big shot") I do know that the heart of rock and roll is one of the three ingredients you need to start the mix master. It's the standup target to the right of the mixmaster ramp. I guess it really takes a beating because it has been a bit problematic. One hit is spotted at the start of a game and the bag of tricks random award sometimes spots them for you. I think this is the most dangerous shot in the game.