Just took home a 2004 B6 S4 Avant in silver (not sure of actual color name, yet ), with the tiptronic transmission and a black recaro-seated interior (again, not sure of trim level/color, odd neutral marble-ish trim). I'm happy, and my 1995 Mustang is even more happy, as the mileage duty on it is completely removed (now reserved for weekend cruising and HPDE's)
I was hunting A4 Sedans with 6 speeds, and the dealer pulled around this car for me to test. It was a bit more than I was looking to spend, but I'm very glad I did (mi madre owns a near identical twin S4 - 6speed sedan, but same color / trim ). I fell in love instantly, even though I was in an automatic.
So I've brought it home, and I'm learning all about it, and have some questions. I've found at least two modifications, a milltek? exhaust (catback, hadn't looked for downpipe changes, and some sort of cold-air-intake (that I want to remove, its not the most pleasing appearing setup I've seen).
so I'll start with the pics, and then the q's:


Cold Air intake:


Q's: (I've completed the cardinal rule of searching before asking, so assume my search results lacked in one way or another).
Engine: So on this "cold air intake" which just looks like a filter on the end of the maf and some sort of breather, is this hurting the car in any way? What line is that with a breather on it? I was worried it was a PCV line and potentially letting in unmetered air in a roundabout way (again, I'm used to dealing with ford-pushrod motors, lots of people put breathers on their valvecovers not realizing they've defeated the closed-pcv system).
I've looked at a couple replacement systems, there's a few options out there, any recommendations?
Body:
I want to make a few small tasteful changes to the overall stock body (preferrably anything that can be removed should I ever be ready to let her go for a new B7/future model).
Are there any simple front splitters that can be attached to the front bumper?
Stereo:
I want to leave the stock system alone, but I currently do not have the satellite radio module or ipod capability, and would like to add both. I've had a really hard time tracking down what I need (as everything I've found is one or the other, not both in conjunction on the Symphony II systems). Any guidance here? The car doesn't have navigation, but I don't know what to look for. I don't care about control from the ipod, just something to interface it, control from the headunit, and basically just set it on random of all songs.
Finally, the car has 38000 miles on it. What things should I check, and are there other mods out there that add to the "experience" signifigantly without taking away from the vehicle's manners? I do wish the tiptronic shifted a bit more aggressively, but I'm so happy to not be daily-driving my "racecar/NVH queen" anymore. There comes a point where lots of rod-ends and lack of rubber in a suspension really start wearing on you.
Sorry for the long post, just excited and eager to learn.

The CAI isnt hurting the car in any way; it just lets the engine breathe easier and (ideally) at a lower temperature which results in a slight increase in power. Same for the exhaust. For B6's you could get a chip but it wont give you any huge gains, maybe 15-18hp at the crank. Can always look into new coilovers to lower (it might already have some, it looks like its sitting lower an stock)and enhance the handing of the car and bigger swaybars and instantly improve the handling. You can get a big brake kit for $1600 or so from ECS tuning. Other than that the next step would be dropping $20k+ for an MTM blower... [:@]

As for the tip, Vast has an awesome chip for the tranny that creates some rock solid shifts that are as quick (if not faster) than a manual. I'm pretty sure its a custom job as its not listed on their website but shoot them an email.

Welcome to the forums man, I'm in the process of buying (possibly)a B6 myself

Thanks for the info!

I meant the cai being problematic as far as its design. Does anyone know what that small line in front (little beneath) of the CAI/Filter is?

I am a new owner as well and doing similar research. I thought I'd read somewhere (but I could be wrong and I don't have a link), that the type of CAI you've got isn't a great design because it's just drawing from the engine compartment without any sort of heat shield. I think you'll notice that after a hard drive motor is putting out a ton of heat and a lot of that hot air is getting sucked right back through that snorkel. I haven't examined the stock filter thoroughly though, perhaps the design isn't that different. If you find other answers elsewhere, please post them here. I'm curious as well.

Josh

It has that shield, which was efective when I held my hand from one side to the other, but its still pretty warm (which anything between the fenders will be that way I guess, nice that they left the "snorkel" in place, as it would provide some cooler ambient air when moving (though, lately ambient has been around 110* in Phoenix, Az).

I set an appointment with the dealer to install the ipod integration, but I'm starting to think the dice unit would be the better choice since I could still retain satellite radio if I ever get the module for it.