I've been looking for a way too add a little more bass to my Mazda without taking up any of the cargo space. I came across a companys website that has a JL Audio stealth box for my car. Ever since i orderd it ive been the happiest. It makes for one UNIQUE ride. You can barely realize its there and it has a HUGE sound output. I'll attach the link for others who want sort of the same thing. You'll also get free shipping with any purchase of $50 or over.

http://www.creativecaraudio.net/prod...76785.6507.0.0

 

I built a custom sub box that fits under the passenger seat - does pretty good too. Just need to use a shallow mount sub is all.