the instructions would be a great help, thanks!Actually, the G's Sirrius Unit Part # is the SAME as the C's.
It's not exactly "cheap" to do, by the time you get all of the Hardware needed to install.
The actual procedure is not "that" complicated, but it requires placing the Sirrius into the Fibreopitc "Loop", which is located in the left rear of the truck, and is next to the CD changer.
If you are interested in tackling it... let me know, and I can look around for the instruction sheet I used.