To resurrect an old thread, this kind of intrigued me. While I haven't done anything under the box, I did rip out the snorkel and take a look inside. The only thing that a modded different than your mod different than Newmission's mod (that was fun to say), was that instead of cutting the plastic under the snorkel location, I wedged a piece of plastic in between the bumper and it. The bumper cover actually had a gap there that was almost seemingly designed for it (realistically not, though). This should theoretically help divert the air almost directly to the intake straight from the grill. Any difference would be negligible, but if I see any increase at all from this then I will probably fab up a fiberglass piece to make the airflow cleaner and give it a ram air effect.
Aside from this, I just have the standard airbox enclosure (w/silencer) and a drop-in K&N. Nice write up.