Been working today on an interface between iTunes on a PC and the CAN bus in my A3 - Just about got it cracked apart from a couple of niggles, one of which easy to solve (double button presses), one of which a bit harder (DIS flickering). At the moment, I can get it to react to the RNS wheel, 2 soft keys, Track skip buttons, return and setup, as well as any steering wheel button, and output to the 2-Line section at the top of the DIS. Hopefully my carPC will sit atop of this once I finally work out what I'm going to use for it!

Youtube demo