Panel is certainly the way to go. I derestricted the airbox and fitted a pipercross panel filter (with vortex technology, sounds good dont it), there is a noticable difference, does give slight induction noise, that complomented by the pre-cat removal dont it the world of good. But now ive had an exhaust made up for it i cant hear the induction, but bloody hell, the exhaust note is sexual. Well worth doing in short.