I agree entirely, started with a K & N with the "protective box", after much experimenting I now run standard Nissan air box with velocity stack and drop in Cosworth panel filter with modified K & N intake pipe. It is also interesting to note that air intake temperature has been reduced considerably by going back to the Nissan air box, I run a Scanguage II and the intake temperature has reduced in average conditions by a considerable margin, I can't remember the exact figures but it does make a noticeable difference So s everyone knows, Pop Charger = noise, standard box with velocity stack and drop in Cosworth panel filter = slightly improved performance