Volume for Custom Box, Door Subwoofers, Kicker Comp C8s

I have 8inch subs in the 2 front doors of my celica but they are free air right now and have no thump only depth. I went with kicker comp c8s for price and easy availability as well as the shallow mount depth powered by a hiphonics thor 2 channel amp. But i can not find the volume of the speaker (the cubic inches that it takes up in the box). Im preparing to build near minimun sized sealed boxes that will fit behind my door panel and clear my window when its down. The box construsction will be custom and a mix of wood and panel board. The panel board will be reinforced by inside cross bracing to reduce flex but for this build clearance will be more important than a little flex.6th gen Ceilca lover

The min box spec is .5 cubic ft sealed but the manual did not specify if thats before or after subtracting the speakers displacement in the box.6th gen Ceilca lover

Isany of the enclosure going to be inside the door? Like between the outer skin and the inner skin?

Yes. The bulk of the encloser will be in between the door skins but need to clear the window in the down position. Currently the kicker speaker is mounted in the factory 8 inch woofer bracket with some cutting to fit the magnet. The speaker sits about 1 inch into the door already. My biggest issue is finding out the actual displacment for my box. I found in the manual that it says .5cuft to be the minimun size for this speaker but the wording is fuzzy to me to if that includes the speaker displacement or not bc the speaker displacement is not listed anywhere.6th gen Ceilca lover