Briefly, with my extended warranty about to expire I ran the Beast down to Audi Taunton for a service and once over by the legendary Stuart Hunt. He reported an intermittent fault on Lambda Probe bank 1 (G130), but the advice was to continue to monitor. Two weeks later (and just outside warranty period) I was on a long run down to S Wales and after a fuel stop, the EML came on. I duly took it to the loacal Audi dealership who ran diagnostics and confirmed the same fault and recommended replacement.
I contacted Audi Customer service (as the car was now just out of warranty), outlined the sequence of events, and after a short pause over Christmas, they came back with "It's out of warranty, but we will cover as goodwill".
Today car has been into Camberley Audi and all sorted in less than 4 hours, all at zero cost to me.
Well done Audi!