My mirror glass was about £34 from Audi. On the net, Vag.com also do them. If the housing is broken, expect a longer wait as they are sprayed up with the colour to match your car. Or another random colour, if your buying from Edinburgh Audi who couldnt supply one in under two weeks. And then it was still the wrong colour...What bit of "denim blue" dont they understand??
Approx £120 for the housing and glass I think.
Thank you Hadwins, supplied and fitted in three days...