If noone mentioned it, Velocity stack is cheap to add onto your filter. My friend just got a velocity stack for his prelude and when I went to pick up a sideskirt from his place today I tried his velocity stack on my civic. Changed the way it sounded and gave it alittle bit of a difference. Nothing to major obviously since it's a velocity stack. But it changes it alittle bit. I might take the one off my integra and put it on my civic, Lol. Or just buy another one...