Thanks for the replies guys...I never even knew there were user replaceable bulbs in there! I was under the impression that they were sealed HID units.
And Ian you're having a laugh aren't you? I emailed A8 Parts on 12th April enquiring about a complete adaptive headlamp assembly, n/s front strut, air compressor (and possible valve block) and never even received a reply.
I also enquiried about the possibility of driving up for them to fit the parts but as I said I never even received the courtesy of a reply.
In any case their price for a scruffy looking strut on eBay was a penny short of £600 where other prices were £240-£450 so not sure I would have purchased from them anyway!
Checked out the air compressor and it does pump up to 16 bar so that might still be OK and I also bought a couple of Philips D2S bulbs to resolve the headlight problem. Decided to replace them as a pair so light output is equal and reduce the chance of the original failing in the near future.
Thanks for your input.
-=Glyn=-