So I have the K&N air filter, and I was wondering, can I leave the air box lid off?? My friend has a SX2.0 and he has K&N air filter with no lid on the air box. Tonight my uncle was checking out the filter, but he didnt put the lid on properly and it sounded bad ass!! Oh my goodness I couldn't believe it, I stepped on the pedal kinda heavy and the sound was sooo much more defined than when I had the lid on properly. So I was just wondering if anyone can tell me how I can get that sound if it's possible, thanks!