I have a 2001 Audi S3 that was having the Concert I volume knob issue. Grabbed a Concert II ( model no 4B0035186L) (Audi TT MKI Quattro 180HP > Interior > Stereo > ES#365818 Radio - In Dash CD Player - 4B0035186L) off a mate for the right price. It is working nicely but the the illumination and ignition power control seems to be having issues. Firstly, the screen is always on at maximum brightness whilst there is no illumination of buttons. Secondly, there is always power to the head unit. In other words if you pull the key out the radio will stay on until you physically turn it off.
Does anyone know the pin outs for these head units so I can try to wire it in correctly (or is this going to be a really big job)?
Of note for anyone looking at this head unit as an option for the S3, it is not as wide as the original Concert I so there will be about a 7mm gap at either side once installed in the dash.