i need a box about 6 cubes or more before displacements to get ~2 cubes per driver to acheive that the box wont fit in the trunk and if i spent the time to make it work i would be firing port and sub into cabin as that would be the only way it would work. there for my box i have which i made didnt fit into trunk from inside the car (forgot theree was some metal in the way, and its too much to cut) i have ripped out my seats and built a wood frame to my trunk floor level was going to do my amp rack and bat rack there, but since box didnt fit its on the wood frame and box covers entire trunk opening thus the same as having in the trunk and sealing off the trunk, just isnt foamed and such make sense?