So I was able to get this installed by reverse engineering the harness and ordering the parts from the retrofit kit that were available. I am doing a writeup of the full process including making the fiber optic MOST bus cables, where to install the fiber connections etc. The two added modules, the ULF-SBX-H and the USB hub each only have 2 connections to the car, one for power, the other for ground. The audio cable from the USB plug connects directly to the ULF-SBX-H, but a different cable is needed from the one that connects to the back of the head unit, the original has 3 wires, L, R and Gnd, the ULF one has 4, L,R,Gnd and Shield.
In the meantime if anyone has questions PM me here.