Quote Originally Posted by Al Fernandez View Post
CMC 6.21.5 Any air filter or air filter assembly may be fitted and OE assemblies may be modified. Air boxes and filters must reside inside the engine compartment or in the OEM stock location. Air filter installations intentionally designed to create, or that appear to create a ram air effect are not allowed, even if they were OEM stock.

Nationals or otherwise...I would suggest not putting yourself in the position of having your hard work tossed on a subjective decision. Its just not worth it.
The "appears" wording is what had me hung up. That is soooo objective that any attempt to create this affect, but play in a gray area of back dating, or arguing any data about atmospheric pressure is negated by simply saying that it appears to be creating that. This word does not require you to actually know for sure one way or the other whether it does. Simply that it "appears"

Knowing that During a protest is burden on proof on the person protesting or defending?