I have 2 idq's sealed in a custom fiberglass box fitted to my tirewell. Approx. 1.2 cubic feet each. My problem is this: I want to have plexi over the subs, but because of the way i built my box, there is a 2.5 inch WALL completely enclosing the baffle. Sort of like a small open top box, 2.5 inches high...
anyways if i put my false floor with plexi windows over it, that will end up creating a dual chamber sealed "box" correct? The back chamber will be ~2.5 cu ft, and the front chamber would be approx .2 ft or something insanely small like that.

So if i just cut out a large hole in the front chamber, will that make the box act like a bandpass? i.e. the hole i cut will act as the "port" on a normal 4th order bandpass?

Or will it act more like just part of the car cabin, i.e. a big 12x25 inch square cut out of the 30x30 top wont really have an effect on the sound?

Ive made a very very crappy and rough drawing of my basic setup if you are having trouble visualizing what i am talking about

here is a link to the picture of my diagram: http://www.geocities.com/opm_lc/diagram.htm