Audio Systems: Cell phone muting car audio, free car kit, hands free car kit

Question
I just bought a new stereo (Kenwood KDC-MP4032) that has audio muting capability (mute wire) for cell phone calls.  It says I need a commercial device to connect to this wire to use the feature.  I have spent far too much time looking for a device.  Can you suggest one?  I have a Motorola E-815 cell phone.  Thank you.

Answer
Sure!  you just need to get a hands free car kit for your phone.  This has wires for Muting the stereo. it also holds the phone, charges the phone, etc. I recomend the S9950:

http://www.cellphonemall.net/wireless/store/accessorydetail.asp?id=13711

And you need the hangup cup to hold the phone:

http://www.cellphonemall.net/wireless/store/accessorydetail.asp?id=34399&phoneid...

GOOD LUCK!