Hey Chris. I have asked you about convertible sub boxes before when I have seen the ones you sell for the hatch model z's. Once you finalize the design, if you start making these to sell, let me know. I was going to hire a friend that's a professional installer to make me a couple of 10" fiberglass sub boxes for each side in the trunk, & have him make me something so I can have a couple component mids & tweeters behind the seats, since the door panel component speakers could use some help. But, maybe you could alter your design slightly to incorporate 5 1/4" or 6 1/2" component speakers into the sub box? Just a thought. I would probably be interested if that's something you could do. Brett.