I changed headlight bulbs on my 4.2 V8 FSI yesterday. The offside can be changed in situ, the driver's side required moving the airbox a little out of the way. My garage charged me £16 for the work, I don't have the tools to do it myself, and for that price it did look a bit fiddly even if I had them
Audi however do quote a fortune however, not sure what they use the time on.....
Obviously the V10 may be different, I haven't seen one under the bonnet.....
C