Four quick q's - have 09 A6 3.0 litre Diesel Le Mans Quattro (08 shape pre facelift)

1,

Tail Lamp condensation - audi say normal? Seems to go a bit when prolonged dry conditions but living in the UK that's rare, only seems to affect the side of the tail lamps and reverse light sections? Any Ideas on cure - third set of lights already?

2,

Drone/humming noise under very heavy braking - (sounds like brakes really biting down dosent sound bad actually a little like a BMW M5 I used to have) is this normal with the 3.0 litre brake set up? However, and also the front brakes have started squealing like an old London bus, told need de-galzing only done 9k miles? Had a few beemers before, never had this issue? Also despite the brakes being quite big circa 350mm vented and larger calipers some fade can be experienced? Thinking of upgrade to EBC Turbo Groove with Yellow Stuff Pads - any one else heard of this or know if beneficial or to the contrary?

3,

I know bird lime or poo is bad with a very big B in big B brackets, but recently got back from a trip where I had to leave the car under a tree in a car park for a week and it was covered in bird guano to my total horror on return.. When jet washed then hot soaked and finally carefully removed the after effects seem to have created a mild melting effect on the paint work - Ooooooo.... tried to polish it out and light compound it - no good - any ideas or is it a body shop job? Surley the paint with loads of wax (Meguires Carnuba) that I have applied just about every week from new 5 months ago should be tough enough to cope with a bit of guano -maybe the menu for aviation dinner for the offending wildlife was a tad over spicy that week?

4,

Also recently had a front wheel re-furbed as during a rain storm the wheel when parking went down a flooded pot hole - deep joy litterally - not!
Wheel repair cant match paint work! Any ideas? It is bright alloy and audi will not so far help with the paint code for the RS4 style 19' rims - just say new wheel.... Oh last bit - tyre was very slighty nicked on the side wall looks like a very light tear about 2mm long by 1mm deep - am changing this and considering keeping as spare as the Pilots are £340 each from quick fit and I am advised that the tyres on a quatrro need to be the same make or pattern and within about 2 to 4 mm of depth of each other otherwise it affects the 4 wheel drive diff????

Sorry for all the Q's new to the marque and forum, thanks in advance though.

 

You have a Le Mans Quattro!!??? WTF? Thats just a concept car....

Im assuming this is an A6 so here goes.

1) The lamps are a vented design, replacing them won't do anything. You can try to dry it out and plug the holes with silicone.

2) Im guessing you park this car outside? In the UK its a little misty.......meaning rust will build up on the rotors overnight. When you first drive the car it will sound like rocks are in your brakes whenever you press on them, at least until the rust burns off.

3) Have a detail tech use a coat of "cutter" with a buffer. This cuts a layer of clear coat right off the paint removing imperfections. This should not be done by someone that doesn't know what they're doing.

4) I don't know about the folks over there, but we do wheel repairs here flawlessly. I don't see why he couldn't match the color, unless he just sucks at it.
I would also use that wheel as a spare with a chunk of the sidewall missing.
As for using the same tires, you are referring to a condition called driveline wind up.
This can only happen if one tire is spinning at a faster (or slower) rate than the other 3 tires. It would have to be a large difference for it to affect the torsen differential.
You could just slap on a tire of the same size (make doesn't matter) without any problems. It really doesn't matter if the other 3 tires are worn either, it wouldn't be a big enough difference to cause a problem. Thats a ploy to get you to buy 4 new tires.

 

http://www-odi.nhtsa.dot.gov/tsbs/tsbsearch.cfm

there are tsb's on the moisture and lights. I can't read the details to know what it is, but maybe you'll get some insight.

 

It tells you that Audi claims it is normal because the lenses are ventilated.