I assumed that too when I ordered one from eBay last week. But I just tried to fit it and for some reason it doesn't work. It's connected into the socket at the back of the HU no problem but the Aux option just doesn't show up when I hit the Mode button, it just cycles between Radio and CD like before. Is this just an issue with the cable or is there some other step you need to take to get the Aux option to activate?

P.S. sorry for hijacking the thread...