I am looking for the front speaker lines from the radio to the DSP amp so I can tap in to get pre-amp signal as suggested by TJJ and Ken. I got this picture on one of the postings by AUS over the Bimmer forum (see attached). This picture is the pix of the radio module behind the battery.
I also got a wiring diagram from Scottdale BMW that shows:

RADLV+: Yellow/Red
RADLV-: Brown/Orange
RADRV+: Blue/Red
RADRV-: Brown/Orange

You can see all four of these wires in the picture. The red and black lines are the ones that AUS and his buddy were testing out the rear channels. In the diagram, these two RADLV/RADRV lines lead to the twelve speakers DSP stereo configuration (which what I have). I suspect that these RADLV/RADRV lines are the front speaker lines that I am looking for but I just want verify before I touch anything. Thank you, folks.

Justin.

Attached Images