C70 Headrest hands free car kit wiring

Hi,

I bought a C70 with a SonyEriccson car kit installed. This car kit uses an
external speaker hidden somewhere at the passenger side and a microphone
above the mirror.

Standard the car came with a headrest kit installed (speaker and mike). I
assume wires to the mike and speaker lead to some hidden place under the
dashboard. I want to connect these to the SonyEriccson carkit.

Does anybody have any clue where I can find these cables under the
dashboard. Some instructions on what to disassemble to find these would be
nice also.

Thanks,

Ron