Yea, I can imagine... I'll be sound deadening the entire trunk and removing the factory subwoofer in the rear deck to allow sound to get into the cabin. If that's not enough I'll make a port right though the middle of the back seat
Honestly id try and build a traingler box or a rectangle box, ur gunna have to favce the sub up and face the port toward the front ad tune it low. Not mjch space i seen worse tje prolem is that zv3 may need about 4.5 cf at min.