After alot of reading, I found a very simple solution to the NAV bypass on my 2012 Subaru Legacy 3.6R factory installed X9310BT (which I just bought). The Canadian cars are wired differently-there is no white RCA harness plugged into the unit. There is a similar white Subaru harness that connects into the black harness which plugs into the back of the unit.
There is an unused purple wire with a button connector on the end that is in the black harness. I simply removed that and used it as a jumper cable from the top (2nd from Left) pin on the unit's white RCA socket and grounded it to the unit chassis. No VSS or brake cable grounding needed. Everything works like a charm! Also, I didn't have to buy a spare RCA harness!
Pic below looking from the rear of the unit:
DSC_0076.JPG 131.58KB 7 downloads