Thanks.
It's an "every other day" daily driver as duties are shared with my equally ancient C4 A6 Avant, which in 2.5 TDI form goes twice as far on a litre of fuel.
I do know someone else locally who runs an even older A8 4.2 QS as his daily driver, and in his case it's his "economy car" as it's on LPG and his other vehicles are 60's Americana whose drinking problems are in a different league!
Nick