Looking to buy myself an A6, have some questions

I'm actually looking at two and I'm having really hard times choosing which one.

No 1: A6 (C5) Avant 2004 2.5Tdi Q with 120.000kms on the clock. Nav+CD Changer, Leather/Alcantara seats.. The works..
- Mechanically the car feels sound. Engine runs really well, gearshifts are smooth. All electronics are working.
Two snags though.
- I have a humming noise that's really hard to tell where it comes from. I know the CV-joints and bearings are achilles heals on these models but the sound doesn't change pitch with speed (at least not much) and no increase when turning the wheel. Any idea what it can be? The boots were replaced about 6 months ago.
- Navigation is in safe mode. I can't even punch the code in. It's showing a bar with numbers on the screen but I can't select any. Is this fixable or is my only hope a new HU?

No 2: A6 (C5) Avant 2003 3.0 V6 with 76.000kms. Not the same options but feels "newer"..
- When would the timing belt need to be changed? Is there any way to check if it has been changed?
- Steering is a bit heavy, would that mean a new servo pump or just a top-up of oil? How can I check this?
- Gives a warning with a symbol with a headlight and an arrow pointing up, The lights seem to be aligned, any ideas?

I'd be thankful for all the help I can get. And also suggestions or reasons for choosing the one or the other. :beerchug:

//Thomas

Looks like the Diesel got nicked by a higher bidder.. Pity because it was nice.. :(

Looks like I'm getting a 3.0 instead. :)

The general rule on timing belt intervals is 60k miles or 4 years whichever comes first.

The next thing for you to do is run a fault code read with VAG-COM or similar, which would most likely shed some light on your headlamp alignment problem and possibly the heavy steering.

Since it's done 76k kilometers I guess I'm ok for now.. But I still think I'll do it right away, just to be on the safe side. I got a quote from a shop today for 2500AED (roughly £450) with Audi original spares and refill/top up of AC gas aswell as checking the servo-pump. Pretty decent I would say.

I'm gonna let the service guy look with his VAG-COM to see if he can do something about the lights

Now I just need to get the CC sorted. Does anyone know someone that can perform this in UAE? I asked the guy who's gonna service it and he could get used spares and fit them to my car. Would that be a solution? I'm thinking about maybe try to get an on-board computer at the same time. Could you just swap the whole instrument cluster? Any thoughts?

Oh, and the headlight warning.. I consulted the handbook and, according to my German which is quite "rusty", it's the automatic headlight adjustment. It's xenon on the car for the running lights so I guess it has something to do with this.. I know that anything having to do with xenon usually gets quite expensive. Any thoughts?