I purchased a used kenwood DDX712 double din and the kenwood KNA G510 Garmin Gps. Having never installed a double din before ...I'm hoping to get input as to what I think is correct. I have attached a jpg of the kenwood harness. A is the kenwood connection. B are the speaker wires. C are not needed (I think) D is a Metra 14 wire male plug. E I dont think are needed. F are hot/ground/reverse/parking brake/etc My problem is the Metra connection, I am going to cut it off and discard it. The speaker wires on 'A' would then connect to my speakers. Vehicle is a 1999 Yukon. Is this a no brainer or am I missing something? Any assist is appreciated.