supposedly the S4 bumper has more lcearence than the A4 bumper...and if it can fit the a4 than it should fit the S4...of yea Im getting the Reiger RS4 kit and Im thinking about the EVOms T-28 300hp kit after that with the APR exhaust and Koni coilovers...also the EVOms oil cooler system aqnd the SPP electric fan all look yummy not to mention the Neuspeed Turbo inlet pipe and that FMIC mister is nice to total cost 10+ grand but it should push me into low 13s to high 12s and still be streetable...oh and lets not forget JuanMs custom lightend flywheels and race clutches fro the DBWs...and the AWE driveline stabalizer to..Im sure theres more but I cant remeber all of it right now cuz Im starting to salivate