In your trunk, just beside your factory amp is a wire harness wrapped in some kind of foam with 2 connectors in it (assuming you don't have a CD Changer). The 3 pin one is the one you should plug into your iBus controller you bought from reslers. The brown wire on the 3pin plug is the ground, carefully look at your controller to line up the ground (you should have 4pin on your controller).
Then use a program named ibuscomm to send hotkeys to your favorite program based on which button you pressed on your steering wheel.
You will find this one by searching over the net