Installing the monitor where the stereo resides is not that hard. Your biggest problem is placing the stereo where it doesnt belong. Since your balls are big enough to try fiberglass when you have no experience, maybe you should try mounting the decks main body under the seat and extend the face plate contacts and make an L bracket and mount the face to the L bracket. That would be easier than fiberglassing. I would suspect that you're using the stereo for AUX in.