Had a similar experience, within one week of the update, car started vibrating and juddering particularly when accelerating and then started to lose power on the motor way. Audi has had the car and identified an injector failure, blaming supermarket fuels. Cost £895 for replacement plus the labour for investigation. Not happy at all! They also deny any link to update, but it's a hell of coincident since a)I have never used supermarket fuels and b)it has always been serviced by them including a week previous when they did an engine flush/treatment as well. Time to get rid of it methinks.
