Hi, Your analysis is interesting as, certainly in my case, there is no set length of time for the fault to manifest itself. The car can be switched of for 5 mins and it occurs, or equally it can be switched off for a day and the system starts up ok. I had already thought it might be something like what you say. But the fact is , it shouldn't be happening and what will Audi do about it? My dealership is quite supportive and have now raised a formal case with Audi UK but ultimately say it is with Audi. Maybe if everyone else got their dealership to do the same, then Audi would need to sit up. Audi already told my dealership to postpone me bringing it in to the workshop as they say there is currently no fix. Quite frustrating. Let us know if you get a fix please. Graeme