Speaker wire was CUT, and connected to the yellow wires and the red connectotr blocks. The sound comes through the car's radio speakers. The radio/CD player will mute when a call is placed or received. Pretty sweet, and not intrusive at all. The only visible components are the microphone and the control button.

Of course, you can spend hundreds more for the OEM kit which will give you controls via the steering wheel controls and I think caller ID on the central instrument cluster display. That is also a sweet setup, but for me, not worth the extra $$$.