ok, so my s was off the road for 2 weeks and before i took it off the road i had grs ic, 17% alta v2 pulley, max air sealed forced induction and magnaflow cat back. when off the road i took the ic and the airbox off and put the standard ones back on. why you ask, just too see wat the difference was? yes thats correct and what did i find. well i didnt notice much but when i hit 4500 rpm the engine sounded better with a louder supercharger whine comming from the standard airbox and i was getting better boost pressure so what begs a question on my behalf is do i really need the grs for safety? or does living in the uk with bitter weather anyway cancel this out?