Hi everybody.
I am from Kline innovation exhausts. I am glad you like our product.
The system you saw is 100% made from inconel 625. Making the cat-back in inconel is a bit exotic , but we can also make it from stainless steel. The system in the pics is 2.75 size.
On dynamic mode the system sounds beautiful, whereas in comfort mode the car is stock quiet without any cabin noise.
http://audirevolution.net/forum/index.php?action=activate;u=844;code=1f1c5aa22d
As we speak, we are making another set of headers for a customer in Australia, with a very nice black RS5.
If you need any other information please feel free to ask.
Felix
www.kline-innovation.com