I said:
and i know from the hundreds of designs i've done, that 2 single six inch aeros is about half the port area you need for a 10 cubic foot box IF it's even 10 cubes anyways, which i highly doubt. hell a lot of SUV's i've worked with struggle to get 10 cubes out of their cargo space. and seeing as that box is only taking up about half of your trunk, i'm willing to bet it's not 10 cubes.
There are VERY VERY few cases where people can fit 2 18's in their trunk. i've seen one infinite baffle setup, and another that i'm pretty sure was sealed.
this is why it's important to plan out ALL aspects of your system carefully before you dive in headfirst.
now, if you're lucky i could see you maybe being able to fit a single 18 in a ported box if it was firing into the cabin.