Sq and loud as can be...bottom bass extension not as important as clean hitting bass on a kick drum, but it would be nice. I do not want to throw a box in the trunk as I will have no space for a stroller. I did a real rough calculation, and figured I can build a false floor with around 4cuft. It will require the removal of my spare, and upgrade to runflat tires...which is fine, I plan on doing that anyways. I should mock up a box setup for the rear deck and see what I can achieve, but that is going to require shallow subs. Where can I hear Fi's infinite baffle sub in southern california?