Sound baffling
I had a '92 Honda Prelude before my MO. I installed a cold air intake (CAI) system which meant removing the stock air intake system. That took 3 hours because of all the tunnels, hoses, ducting, and other crap that made-up the whole system. I even had to remove the front wheel, bumper, and fender lining just to get it all out! Most stock intake systems have several design goals: 1) cold/warm air management, 2) control air flow (less bog at low RPM, freer flow at high speed), and 3) sound control. Previous to the CAI I had a K&N filter that replaced the stock filter in the stock intake system. There was little difference in sound or performance. With the CAI installed, the intake ROARED with a noticable difference in performance (most gains were noticable at higher speeds). So in a Mo, you probably won't notice a sound difference for the reasons mentioned above.