The stock intake has two resonators which significantly quiet down the intake noise. The big resonator located at the front right corner (you have to take of the bumper to get to that area) does most of the work. Without this resonator, the stock intake is much more obnoxiously rumbling loud, especially at higher revs.

Since intakes really don't do much for power, I'd go ahead and put that stock intake back in and put a K&N drop in... better than getting harassed by cops (even if they shouldn't be harassing you in the first place... the reality is... IT HAPPENS).