The bill - £587 + VAT for parts plus two hours labour (£240 +VAT) - oh and a three week lead time.

So what were they fixing? Well, the leveling mechanism is managed by two white cogs (about 15mm dia) sitting on each side of each lamp unit. One of them had broken (apparently a known fault) as the plastic perishes over time because of heat from the engine.
It would appear as usual, that Audi's solution to a 20p problem is to swap the entire unit out - there are no sub parts available. I suppose I should be grateful they didn't suggest swapping the Bi-X ballast and bulbs too.....

Has anyone else experienced this and if so, did they find a more satisfactory solution? If not, any bright ideas?
I've looked for a donor unit, but the usual world of part numbers etc. has made it impossible to source one (how many different part numbers for an A6 headlight??!!)