I might be going, but I haven't got a ticket booked as I was just going to turn up on the day. I won't be in my Audi though as it's off the road needing an engine rebuild.
I know on the A6 c5 induction kits etc are pointless and the stock airbox is actually best. You.might.be better going for an.upgraded panel filter from k&n ect. As heat soak will be your biggest issue with induction kits.
I'd recommend a diagnostic check to see if any fault codes flag up. The knocking in my case on my old a6 is the crankshaft. Hopefully yours won't be that bad.