Since my vehicle's sound system has RCA inputs, I connected my iPhone to it via the Shure MPA. Now I can listen to music or podcasts through my stereo. When a call comes in the sound fades, the iPhone rings and I answer the call through the MPA. I can here the caller through the stereo and my voice is picked up by the Shure's microphone. So far I have heard a little echo but no feedback or other problems. It makes a reasonable hands free system that works pretty slick.