Hi Marky_mark, thanks for the offer, I may take you up on that but now have a couple of things to try first.
I've found an independent garage in Guildford who seem really good - bloke was straight up to speed on the car and ID'd a couple of points which are in contrast to the official Audi guys who apaprently know the car. Will be interesting to see who pans out right! More info to follow on that.
As far as the stereo unit goes, apparently the head unit gathers signals from the chosen source and feeds them down signal cables to the amp in the boot space. If the amp loses a signal it produces the 'bonging' sound. The +/- buttons on the steering wheel dont work either, and there is a Parrot hands-free phone system installed, the head unit for that is also dead.
The guy took the head unit out to check cables etc are OK and although they appeared to be, he couldn't get the unit to work. When I drove the car away, the CD player worked fine for 10 mins... then went back to bonging sound. Switched to radio, works fine, tried CD again, worked fine for another 5 mins.
We suspect the connector pins on the back of the stereo head unit have been damaged by someone chasing down the Parrot head unit and/or steering wheel button failure. Being moved has caused a partial-reconnect. We'll try re-pinning the connector and see how it goes. Could be a nice cheap fix!
