Ok thanks! I guess all there is left to do is try it! I might ditch the plexi though, MDF is stronger, it won't look like there's anything in the trunk.

I'll probably make a minor change to the design though... mount the subs traditionally instead of inverting. That way if I don't like the sound I can just flip the box around and point it backwards.

Unfortunately I don't have a surplus of $$ to use on box material to try different setups.

I have received a suggestion to build a ported enclosure for these particular woofers. Is it possible to build a ported box that sounds "tight"? (I like tighter bass) Or should I just stay with sealed.

I am not so much concerned with volume as I am smooth an clear bass response.