I have and have always just removed any resonation chamber junk and just ran a K&N drop in. I have this done in my Max, MY Protege, my CRX, and my civic (pre boost). The power gains are minimal but sound is what is important . Also I would rather clean a filter than have to go spend $8.00 on a new one. My cousin spent a shit load on his V2 for his EVO and I barely feel a difference. But then again he loves to blow money so..... If you barely feel a difference on a blown car then what the hell makes you think you will feel a difference on a NA car. The best bang for my buck to date (except the snail) has been the P&P done by force10.