Any gurus out there, that can help me.

I'm wiring the speaker output on my Nokia Car Kit into the Clarion radio on my P38. I've found the Attenuators for the door amps, so i'm going to tap in there. But have two channels and CarKit is mono. If I just split the cable it will bridge the two channels. Any Idea on how I can stop this?

If anyone has a schematic for a Clarion Diversity Radio, could be helpful.

Stu