good disscussion, i agree with james, the filter box is big enough and the air intake is in a perfect position for a rear engine car, how can this be improved upon? why fit an induction kit apart from the noise, there is more chance of picking up preheated air from the engine bay wheras the std box is sealed to the outside of the car.
personally if you can get a bmc filter to fit the std air box this will be the best option, have seen loads of upgrades on bikes using the bmc with impressive results on the dyno (the wheel of truth).
a dead cert way to prove if there is an increase is to put a portable scanner on the car like the snapon solus etc, log the outside air pressure with the engine off through the map sensor, then drive the car and map the intake pressure, the system with the least pressure drop is the one to go for. sounds complex and a fuss about but it would settle any argument. i did this with a standard filter and then a pipercross in the std air box and saw a definate improvement,
i will of course expect loads of comments, please read my post on fuel pressure.
