How did the sharkfin get removed without leaving a hole in the roof? It could not have OnStar without it. Just a quick look on the glove box door would settle all of that; is there a problem with that? You could take a picture of it so you would not have to bend too much.

If you really want the part you will have to buy a new headliner and get someone to figure out the body harness, I can't find any details about it.

Dealerships don't do custom work, their mechanics are strictly parts replacement people.

Here are the option of mirrors available:


The 25603373 does not seem to have the map lights. My 2008 and 2011 both had them w/o OnStar w/o dimming. Maybe there was a 4th option? Do you have sun roof, that would explain it.

All of the wires needed could be pulled from the BCM under the radio in the foot well up through the windshield trim and fingered through the crack under the headliner. But there is no EASY plug n' play way to make the mirror that you have work.