Benny makes a good point - breathing out easily is one thing but you also need to be good at breathing in. Newton's doing some work on the 4200 intake but does anyone know what the downside is to an exposed filter like the one in the Trofeo pic above? My point is, why by default are air filters tucked away in a black box at the end of some plastic guttering?
First, the OEM design is not too good. See where the OEM air box in our car is ? Try to drive through a water puddle deep enough and.... you will hydrolock your engine! Then you're good for a new engine.
The only downside would be to get hot air into the engine instead of cold one. This said, if you direct fresh air onto your intake you'd be good.
Will the filter fit? For sure you'll have to remove the plastic covers first, then I wouldn't bet that it fits since the bonnet plunges down quite fast. The only way to know is to try. So if anyone finds a spare intake manifold, it's worth a try. Noise wise, it wouldn't do much more than a BMC in your stock box.
The only tangible thing would be to get flow figures for the 4200 intake manifold and the intake manifold on the GT