So, every year I take off as much as I can and store on the boat shelves in the heated basement. I have not been removing the AM/FM/CD or even the faceplate. After last winter my 2 year old stereo had some issues with the display only partially working. Coincidence? Frozen display? Don't know for sure. This fall, new boat, new VHF, new stereo, I will remove those. It appears that the control for the autopilot and the instrument display were never meant to be removeable, at least easily. GPS always goes home as well.