Right the undertray just came loose on my avant, dug into the tarmac and ripped off in bits taking the gearbox tray with it. I took my car to MB Services Sheffield on Monday and they had the tray off. I gave them a complete new pack of fixings for the tray as mine were rusted so this is the last thing I expected. Question is, do I need one and how expensive are they to replace as I would rather have one as Audi intended. They will be getting a call Monday as they got water in the ballast of my xenon which has blown it and some how managed to get water in the car too when they washed it. Not a happy chappy.