I have installed the BMW DSP subwoofer into my E53 non-DSP vehicle.
I used the high audio input from the existing wiring on the left side rear area
My parallel wiring scheme for the two 8ohm dual voice coil DSP speakers equates to a a 2ohm load. Essentially, running all the positives together to a single positive speaker connection put into the bottom of the box and you run all the negatives to the negative post of the speaker termination. Then run the output of the mono amp to the new single speaker terminals that you have put into the bottom of the DSP box.
Factory DSP box attaching Hardware: 65106905660, 07119905720, and two 16131183133
My Power Acoustik RZ1-2300D mono block amp is happy with that and is rated at 1400 watts @ 2ohms.
This can help you find the twisted pair wires to tap into to feed the high input side of the amp
http://www.xoutpost.com/articles/x5/...ctory-amp.html
After ejecting the connector you should now see 2 connectors side by side, a gray one and a black one. The pins are numbered from 1 to 13 on the gray connector and from 22 to 34 on the black one. The pictures 6 and 7 below show the 2 connectors. On this connector Pin #1 (-) and #2 (+) are for left rear woofer and pin #24 (-) and #25 (+) are for right rear woofer.
Here is my install
The RZ1-2300D is narrow enough to fit in this tight space between the spare tire and the body
Mike