A shunt is an electrical component that if I'm not mistaken helps redirect the flow of current if some circuit is overloaded. In any case when the above spy-photo of the interior was posted most of the people here were unaware as to what it was and it became a joke that "Shunt" was a guy that asked FBodFather about the pre-pro headlights 1 time too many and was "taken care of". That sign is to remind the testing engineers not to freak out when they hear screams coming from the trunk!