Was your problem ever resolved Cooper? We have found ourselves with the exact same fault with our A1 (68 reg) and the car was sold to us by Audi used dealer with a ‘makeshift earth repair’ on one side which has now burnt out again and the other side is heading in the same direction. We’ve only had the car six months and have an Audi extended warranty for another 6 months. Not sure if it can be fixed under that. But if the fault reoccurs it leaves me nervous.