Ive got a k&n on mine, sure its sapping loads of power. Guy never gave me the original airbox, so got the option of trying to source an airbox or put the money towards the above.
ive got the ITG/MAXOGEN induction setup, its running fine however im not too sure about it i mean yes it sounds nice when accelerating but i dont think it puts the car up in any performance way at all feels a little different to the normal air box especially when the car is cold