I apologize, what I mean is the wiring diagram that connects to the factory radio. I have a 2008 RX350 W/nav without ML system. I'll be getting the Pioneer AVH-4200NEX this Friday and I also bought the idatalink Maestro SW to retain the steering wheel controls. The issue that I'm having is the Maestro instructions tell me to connect the wires to the factory harness...see attached...would tapping into my factory harness be absolutely necessary? or could I just splice into the pioneer headset wires? any help on getting this install done would be much appreciated
NEWPIONEER-Maestro.pdf