That's good for the non-Bose or if you replace the speakers also. I have the correct Metra adapter, I believe it is the 70-1764. In either case, there is still a wire on the adapter that corresponds with pin 6 "joint harness" of the factory vehicle connector. Metra identifies this as ground vs joint harness. The only other wire from the new head unit harness not hooked up is the chassis ground. So is the "joint harness" actually a ground that I need to hook up to the chassis ground? Thanks