I have this adaptor that allows me to run my MP3 player through my car radio by plugging the adaptor into the cigarette lighter. So how does the music get to the radio? I don't think it is making the car electrical system broadcast to the antenna. So I am thinking it simply forces the music through the power line into the radio amplifier. One interesting thing is that there can be a radio station broadcast but when I plug in the adapter (w or wo the MP3 player attached), within a second, the radio goes blank. That is harder to figure than that the music must go in thru the electric line into the amp.