So I decided to investigate my airbox yesterday, just to see if there were any factory obstructions in there, such as a metal water screen or anything that I could take out. Unfortunately there was not. It looks like Mazda does not have anything restrictive in there. In addition to the front snorkel tube which sucks air in from under the hood, there is also a side tube. I really wanted to remove the side tube, to just have a big gaping hole in the side of the airbox. Unfortunately Mazda has made the front tube and the side tube non-removeable. The tubes clip-on, and then there is no way to take them out without permanently breaking the tubes (which I will consider once the 50k warranty is up). Most older vehicles have tubes which simply slide on or off of the main air cleaner housing, but in this case, they apparently do not want us to be able to remove these tubes. So I was out of options, until I noticed 3 small factory holes in the bottom of the air cleaner housing. Since they serve no purpose (must be manufacturing holes) I decided to drill these holes out larger, and then drill a 4th hole, for a nice clean looking swiss cheese effect. I don't know if this would technically "void" my warranty (would be pretty hard for a dealer to make a case), but once i'm over 50k, I plan to add some more swiss cheese to the bottom of this air cleaner. While I had the airbox out, I observed yet another control module in the engine bay which just reaffirms that the cx-9 really is a computer on wheels. I also noticed that the starter had Japanese lettering all over it, so clearly the starter is not a Ford starter, so this tells me that the Japs perhaps took all the crappy Ford components off the Duratec engine, which is refreshing.
