Ok So after hours upon hours of audiophile research heres the deal, if you’re going to put a system into a BOSE 2019+ then you need the NAV TV Unit. Period. It converts the bus data signals to optical/digital or coax and allows the cleanest signal possible with no time alignment issues etc. If you choose to use a harness, (which none on the market to date have zero interference), or if your like me who figured out all of the wire connections on the amp and spliced from there, you are going to need a DSP since the issue with the bose amp is mainly some timing correction that cannot be altered with an LC7i. For the non bose, Im not entirely sure but again the NAV TV unit is without a doubt your best bet for the cleanest possible sound and best bang for your buck build for an audiophile grade signal. I have tried everything, I will also be making a color coated wiring diagram for all the speakers and amp input/output for those who are not going to to buy the NAV TV unit. Again, no matter what, you are going to need a DSP regardless if you have bose or not. Otherwise its not even worth the money upgrading. The whole issue is these newer trucks have converted the signal from
the head unit into BUS DATA which obviously is not able to be used by aftermarket amps or DSP’s. So the NAV TV unit essentially changes those pre amp bus data signals into digital or analog allowing you to actually bypass the bose amp or factory amp without losing all of your door chimes etc. If you dont use the nav tv unit you are going to have to tap into the amp post amp signal, and use a dsp to clean up the incoming signal as best you can, then have the dsp convert the signal to rca to be able to plug into your amp. Again you will need a dsp no matter what because the signal coming through has its own factory time alignment which will not suit any aftermarket system you install. As far as tapping into the truck, there is a wire cluster under the passenger rear sill panel, but its best to remove the rear seats and tap in there since its much easier to clean up the wiring mess. Currently Im waiting on my NAV TV unit so Im going to be soddering back all those wires I spliced and when the Nav Tv unit comes In Il install that and send a digital signal to my DSP then send the signal to my amp and finally have a truly worth your money audiophile grade sounding system.