Update #2
Removed the 996T to install an audio plug with a 90 deg elbow and to get rid of those gigantic RCA plugs . You can see the mess of wiring I did. The power for the Uniden comes from the Alpine's harness. Everything comes out all at once ---except for....the Garmin GPS Cable that I had to feed down into and behind the A/C controls, so it takes a little bit of elbow grease to get it out, and back in.
After soldering, wrapping the audio splice with aluminum tape, and encasing with heat shrink tubing, the whole mess was once again 'tied' and pushed as closest to the back of the units as possible....