On the inside top of the hide? I don't know where else it could be really it will be a pain to clean there but that is where it makes the most sense if it were on the face of the panel ambient temps would change the hide temp dramatically. I might be tempted to run a fail safe too attached to the panel (failsafe probe) and set to 100ºF or so so incase the panel got too much hotter it would shut down and not risk a burn.