Can anyone offer any advice on a intermittent fault I have on my 2006 A3 quattro. The car has 60k on it and what occurs is that the "overboost" comes into effect and it goes into limp mode(around 3000rpm) and I have to cycle the ignition to clear it. This does not happen every time and the car has just had a full service. The fault register on the ECU but obviously the cause of the problem is not highlighted on the VAG diagnostic system when the ECU is interegated. The car usually pulls like a train and there are no other problems apparent. Any advise would be appreciated.