IIRC, somebody had a similar issue once before... Let's look at what they all have in common:
OK, the suspense is killing me!!! Spill it!
I know this has already been resolved but did anyone think that the parking light issue could have been as simple as the illumination wire in the radio harness and totally unrelated to the GEM? If the radio harness melted the illumination wire probably made contact with the keyed power wire for the radio. Turn on the key and the wire has power and is shorting over to the illumination wire. The radio lights normally dim with just the parking lights on so it sounds feasible to me. I might be totally on the wrong track but it made some sense to me.