Bought this item for AUD$55 shipped to Aus:

It's the Simota Panel replacement for 2004-2012 3.8L Galant/Eclipse/Grunder/Endeavor.

Definitely revs in the lower range a lot quicker and sounds deeper (Already have 90mm Galant snorkel, and cut lower resonator mod). Butt dyno likes it, but I suspect it flows better than the K&N I tested because this is a dry mesh filter as opposed to oiled (and sometimes over oiled from new) K&N that seems to have mixed results for everyone here.

Either way, my finding is to your benefit. Enjoy!

PS Any aftermarket filter that replaces the below Mitsubishi part numbers will fit even if not advertised specifically for the 380 as the airbox is engine specific: