Lol! My wife may have just made this solution real simple! I was showing her the pics of how I spent my morning... She made a halfway sarcastic comment about me fixing the shower wall panel when I put it back tgether (one of the plastic push-pins never seats right, so the panel pops loose all the time.) Not a big deal, but not worth tearing it apart for no good reason so far....
Then it dawned on me: The only thing holding the shower surround in place is a few of those push-pins and a couple beads of silicone at the top edges! I *think* that if I pull the tub surround I may be able to see into that cavity behind it! If I can, I should be able to see both the marker light and the taillight and make a working repair REAL simple!!
If this works, my wife gets all the credit!! (Hey, even a blind squirrel finds a nut once in a while, right? :P)