what to look forward to
 

i will pick up an 05 A8 with 74k on the clock this afternoon. i understand that in a few miles (app. 80k) i will face a timing belt, water pump and probably thermostat replacement as well as a trannie flush and probably plugs and filters. are there any problem areas i should be aware of or signs i should be aware of relative to problems. i am a bit familiar with the car as one reason i got it is that i am relatively very happy with my vw phaeton.

Well, unless you do your own maintenance, I guess you realize that you're facing a small fortune in the scheduled maintenance you listed...maybe a bit cheaper at a qualified independent shop compared to full dealer price.
And by reputation, you should face infinitely less electrical problems than with your Phaeton (your past experience may vary)...plus about a thousand pounds lighter...much more nimble and sporty, but still with a great/quiet ride.
The front air springs on the A8 are reputed to often need a rebuild around 100K miles or so, but other than that ?? ...D3 owners may have more to add(?).

Not sure how applicable these are to the '05, but the trunk motor/latch was an issue on the '04s, and coils may have to be replaced as you approach the 100K mark. Audi started replacing the coils on their dime, but I do not know if that was only on cars that were still under warranty.

l8r)

Don't even think about it, it's a $16 part, but the labor to change it at any other time would cost you about the same because they have to go through the timing belt and water pump to get there.
My advice, especially if you get a mechanic to do the work, is to replace everything you can during that service, all your idlers/tensioners, even the serpentine belt. The cost of the parts is trivial compared to the cost of the labor.

thanks, i did wonder about ease of getting to the thermostat, only mentioned it because i read of some problems with it at about 35k. i do have a mechanic i use TOO regularly who seems quite knowledgable about most cars (he also does rr, maserati, etc. and owns a ferrari). obviously, so far i love the car. i think i got lucky with it. one owner. highly optioned. free period of xm radio. hell, the manuals look as if they were never opened, no dog ears, notes, etc. on them. as i mentioned in another post, only the keyless entry seems not to work. i figure this is a design failure because i have exactly the same problem on my phaeton and the systems appear identical.

There is a central module that controls keyless entry operations...not sure where it is in a D3...it's in trunk left, ahead of cd/nav in D2....fuse, coding? ...Should show on a Vagcom diagnostic.
And agreed, ALWAYS change the thermostat, if you're "in there" anyway...they always go bad eventually...might as well add some more miles of confidence.