So as above picture shows ( real image not the exact but it's the same, with the remote, wire, and the MP3 ) I bought it yesterday, everything works, but 1 question, just want to know, what does the wire on the right hand side does? I can plug it in on the MP3 side , but for the other end of the wire, where do I plug it in to? I don't need that wire to play my MP3, so what does it do?

connect to ur phone perhaps?

Tried, nothing happens so I guess its not

connect to headunit aux in port so you dun use the crappy fm frequency to receive the music.

I don't see my car having the plug in for it , where is it located ?

1st end should be on your media player/phone and the 2nd end should be connect to your mp3 player..

my guess, the cable should be plugged into your HU and portable devices..

So basically if my media ( the radio part ) doesn't have the plug in, can I plug one on my iPhone, and the other plug into the MP3 itself ? So it means it plays from my iPhone? I did try that earlier but nothing.