I love the S5 lads. Have spent a bit of time looking at the dirrent exhausts available for it. First clip is the difference between the standard (which sounds very angry for a stock exhuast) versus the almost smooth refined sound of the custom miltek.
The second clip is a custome AWE exhaust. WOW... seriously... the best sound I have ever heard out of an Audi. unreal!
Stock versus millteck ( i prefer stock)
Stock versus Miltek From Youtube.com
(awe custom.. holy chit)
Custome AWE exhaust From Youtube.com