I highly recommend Milltek exhausts, an Audi technician told me that it's the nicest sounding exhaust for these cars.
The car is rated at 420bhp as standard and independent UK testing has shown power gains of up to 20bhp on the final Milltek production cat back systems! We're looking forward to seeing what the improvement will be with the manifolds and downpipes / high-flow catalysts as well!!!
The system has seen testing at many racing circuits and has received overwhelmingly positive feedback.