Since you have the non-DSP system, it is easy to pick-up low level, front channel, pre-amp outputs from the radio. You can find the pins on this diagram, depending on which radio that you have. Alternatively, you can get the same signals from the amp located in the trunk, but I do not have a handy post to show you which wires they are.

http://www.xoutpost.com/articles/x5/s...formation.html

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