OK - Apparently, the clunking and banging is my CV joints....
A possibility I concur.
So.... Having looked into CV joint costs, I have 1 inner which I think is shot, and 1 outer I know is shot. Meaning 2 CV joints. So the parts are going to be up towards Ł100.
I have also found somewhere that is willing to offload 2 complete low mileage (38,000) driveshafts from a 2000 TT for good money. This seems like a better deal to me in all.
Question is, will they fit the S3 Quattro?
I would look on ETKA - but it appears to be busted.