Ive been searching around and trying to find if they can be made to fit. I saw on a forum that a guy had them on his S6 and said they were compatable with the A6 4.2 also. The pipes look like the same lines as my car. I have the chain driven 4.2 just like the S4 and S6.
There are no Milltek downpipes for the C6 S6 (which is a v10) or the C6 A6 4.2. Im 99% sure, the guys you are quoting are talking about the C5 A6 4.2, which is a totally different engine and car.
Your best option that I know of, would be to gut the cats and get a JHM tune. JHM headers would be the best option, but there are none for your car at the moment. The B6/B7 S4 headers would probably bolt up to the engine, but I doubt they would line up with anything else.
You seem to be ready to dump a bunch of money into the car. The problem is, you are starting with the wrong car.
If you had a v10 S6, you would have all kinds of options. Any chance you can trade yours in now, before you spend a bunch on mods, and get an S6?
Any belt driven won’t work as the motors are different over all size. The A6 has less body room then the S4 if that helps so they don’t fit either. Now you can make anything fit and I’m sure you could spend enough time to modify them to fit but if you can modify them to fit I would suggest just making your own at that point.
Well i am co sidering making my own downpipes but i just dont want the car down for a long period of time while i make them and then go through test fitting and re-making or welding. Selling the car to find a S6 would be out of the question as the price bump from the A6 here to S6 is double the cost. I was looking at S4 B5 before this but didnt like the older model look.