This thread... Idk or pretend to know the Op's goals but it seems to be "make it fit"... lol
Maxx space is what 40w x 13h x 20d?... omg
A single 9512... fine. 13.5" od and 9.75" depth... I'd let the frame hang .25" top and bottom while being sized/ported for your power if it was me, unless you find another .5" in height somewhere... idk... it's your car. (I can't measure it).
12.1875" mounting cutout even... doable as hell
Why turn it into a debate Imo... it's doable... and will probably make you think tour trunk is coming off... lol
Unless I missed something or am wrong this'll fit and do great on your power...
I mean... comon' a m3 would be slammin a 9512 @ 1 ohm but not killing it imo.
14-16in2 of port in 2.5-2,75in2 of net volume ought to do it for a SINGLE 9512.
That's roughed in with Torres only. If I had to design something I'd take the time to model it for sure... then draw it up.