Looking for help from The BRIT
As far as service manuals go, very hard to find for the A8/S8 in the UK, in fact almost impossible to get any information at all.
The Bentley manuals shouldn't be too different from the reality of a UK car, the main differences between the US and Euro models seems to be what options become standard fit, although there is a possibility that gearing ratios (possibly just final drive) were changed in the US S8.
You may not be able to rely on part numbers though, as many A8s in the US are the long-wheelbase variety and part numbers for rear drivetrain componets will be different as will headlight and bumpers (to think of 2 off the top of my head). Most other stuff in the US should be fairly similar to any Euro LHD car, so the usual part number caveats apply there too for a RHD UK car.
You could try <a href="http://www.carlounge.com/cgi/cars/frameset.php/pageid/books_makes_audi_manuals/useframes/Y">here</a> for a supplier of hard to find Audi service manuals, but I don't know that they sell A8 specific stuff, or if it even exists.
I'm surprised at how little information leaks out of dealer techs, although I know somebody released a self-study guide on the 4.2 V8 engine as a PDF a while ago.
Finally, you could also try some UK Audi forums if you haven't already, although the A/S8 forums are usually pretty dead! Try tyresmoke.net, rs246.com, and audi-sport.net for finding more UK Audi petrol-heads. If you don't read it already, you might find that Audi Driver magazine is useful too, see <a href="http://www.autometrix.co.uk/">here</a> for info.
Good luck, let me know how you get on. You can usually find me on here or over on either tyresmoke or rs246. If you register for one of those two, you can PM me if I don't show up for a while. :-)
Ta
Steve



