Unfortunately a subwoofer is not an option... the system is going in a 2005 Lotus Elise. Since the car is a daily driver, completely removing the stereo (which i know some of you will say) isn't always the best option (no matter how sweet the exhaust is). But ofcourse weight and size are still important. The head unit and stock blaujunk stereo have already been upgraded to a pioneer head unit and mb quarts but it's just missing a little bit of lows. So even if the bass is just "ok", it would still be a vast improvement from where it was. So if you have any experience with them please post.