Finished this install last week. Thanks a lot for the writeup.
One VERY IMPORTANT tip I would like to share is that you DO NOT have to try and fit the retrofit wire through the rubber grommet. I simply put it on the right side of the rubber grommet towards the windshield and closed the overhead light console. It is not noticeable at all as if something extra is out there or not. Looks untouched. It saved me a lot of time and a great option if you can get it to look right. My rear view mirror cover closed completely which helped in hiding the extra wire much more effectively.
Another tip (actually should be part of the steps) is to REMOVE the little individual round light caps. This will enable you to see the metal clips in the back. I had a hard time getting the metal clips off using everything from a spatula to a screwdriver. I realized I was actually pushing up on the clip, not in between the clip and the base where I needed to, to unclip.