Here's the modified harness as described in my third post - it's based on an AX-NIS-ADDCAM1 harness adapter - but slightly modified.
The Black and Yellow wires wrapped around the harness are a part of the harness adapter and are not used at all - I could have cut them off but I'm planning on using those for another Leaf modification later
Let's get a closer look at the connections:
In this angle, I have the female end (the end that the male connection from the car plugs in to) at the bottom, and the male end (which plugs into the stereo) at the top.
Let's start with the top row of pins from the male connector (to radio) in the top half of this picture. There are six wires which are connected 1:1 - that is - they go from the same place on the car's harness to the same place on the new radio. Other than the 6 pins connected at the leftmost connection on the top row, the entire top row is empty as it connects to the new radio - but not so on the female end which connects to the car (bottom half of this picture). Although the 6 pins are present - there are another two pins (green/white and blue/black) occupying that row as connected from the car. These are carrying the MIC+/MIC- and need to be moved to their new location - this happens to be on the second row.
Here's the second row:

Now, this is a little confusing to look at, because these connectors aren't really "side-by-side" like this in real life - so the connections are flipped. The left plug is the female (to car) and the right is the male (to radio). You can see where the green/white and blue/black connections are coming from the car (left half of image, top row, left) - and now where they're going to (right half of image, bottom row, right). In between those pins there is a red wire - this is the +5v output from the radio which is providing the mic power through a long wire down to the BCU harness.
If you refer to the images in my first post, you'll see that only 4 of the top row pins are probably needed (as the old radio had 6 pins and the new one only 4). This would mean you could possibly use the existing wiring from either of those two pins (the old radio used them for COMM high/low to the BCU, now removed from the car) as your method of delivering +5v Mic Power to the trunk - saving you from doing what I did and running a new wire to the trunk. I don't know if you might damage anything running current through those wires - obviously only try this (or anything I posted) if you are willing to take the risk of damaging stuff - but hypothetically, what you'd do is move one of those two spare pins from the top row between the green/white and blue/black in place of my red wire, which runs to the trunk to the BCU harness, and then patch that to the Mic Power input.
More pics later!