Dont mind the mess, I actually installed bracing under the sub that holds it in place.
The strut tower brace also helps. The box is 36x10x6. The inside walls are spaced in
a bit, to keep the subs from having too much room. This box design can be built with a total of .91 interior space. Mine is partitioned.
The cargo door they are sitting on is open, so they fit a bit down into the opening.
The spare tire cover still opens just fine.
Overall, the fit is perfect. It doesn't move, period.
The Arc 8s are VERY good sounding subs. Punchy, and low end isn't bad at all for 8s. I'm only giving them 90 watts per side (Rated 150 rms.) I find myself turning them down.
The box can't be removed without pushing the seats down, and wrestling it out.
Still looking for grills for it....