I had planned several years ago to get an aftermarket intake for the Box but, after examining the stock unit...it's a cold air intake stock. At $300 for the Evo, my desnorkeled stocker is fine. I understand you get a throaty sound but, I'm confident it's not $300 worth of cool. Especially since there's no real numbers on hp gains, yeah sure they claim 10-12hp gain but, lets be realistic. A reprogram of the ECU would be something I'd rather invest in.
This is just my two cents.