MILLTEK SSXAU875 Cat-back 100 GT AUDI S4 4.2 V8 quattro B6 Saloon/Sedan‚ Avant‚ & CabrioletDescription MILLTEK SSXAU875 Cat back 100 GT AUDI S4 4. 2 V8 quattro B6 Saloon Sedan Avant & Cabriolet Cat Back systems are designed as direct replacements for the original exhaust, offering improved sound and aesthetics. Multiple configurations are available, allowing the owner to select the desired increase in exhaust volume and a more aggressive tone if preferred. All products are manufactured from 304L aircraft grade stainless steel, ensuring