I hang my temp controller on my lap clipped to the edge of my chaps. A friend velcros his on the plastic cover between the radio and the GW badge below the ignition . If you have one that will be permanantly installed, I have seen them on the shelter above the radio, on the right side pocket hard cover (nobody seems to use that anyway) where the CB would go if you don't have a CB and on a plate the replaced the GW badge that is above the radio.
BTW - vhere in da UP are you'se, eh? (Copper Country poikka myself)