Hey there.. Yea, my mods on my S4 include a SuperSprint Race System Stainless Exhaust, Stratmosphere Diverter Valves and Custom tuned AutoThority Performance Engineering Software (1 bar of boost) to bring it all together. My car has been pretty bullet proof but it only has 22K on the odometer. I have not tried a short shifter as I have been spending money on Audio Gear and Music. Imagine that.. If you ever want to talk cars, music, or gear, let me know..
Chris
Chris