Milltek Sport Audi RS3 Saloon GPF Back Exhaust System (8Y)Milltek GPF Back Exhaust System for the Audi 8Y RS3 Saloon transforms the sound of the RS3's 2. 5 5 cylinder TFSI engine whilst retaining the factory OPF filters to keep emissions 100% compliant. The system runs from the OPF to the tips, with the choice of a resonated or non resonated section depending on your personal preference. The resonated system is the quieter option, whilst the non resonated pipe is straight with no restriction until the