Hi y'all,
Some know that I am a hobbyist audio builder and I definitely enjoy conjuring up unique designs when time permits. I've been working with another Flex member and have come up with a few different sub box designs ideas I'd like to share. My goal here is to offer up some ideas for hidden sub boxes and for those that would like me to fabricate one for them, I can possibly provide that as well. I'm working on prototypes but I've modeled them in Sketchup for a baseline design, to make sure I'm able to even build it.
First design is one that can fit behind the 2nd row seats, in the floorwell of the 3rd row. The box design allows the seats to flip and fold per normal. The only space taken is the floor room back there, so either you'd keep car seats with little kids back there, or you could pull the box quickly for adults if you ever have them in those 3rd row seats.
Here's a rough 3D model that I uploaded of my design plan. It holds an 8" sub.


A pair of these boxes could be implemented:

I've also got a side-firing single large box I'm working on, no pics on that yet (too ugly.)
Another box is a spare tire well box. I made my own box for my own Flex out of fiberglass, but the cost of materials and time to make something like that is prohibitive for most. As a result, I have been working with wood on a new design, which uses a geometrically perfect shape that the spare tire well actually turns out to be. Looks a little like this

But of course the top is dependent on the sub(s) used. A design I'm working on right now involves too very powerful Sundown 10" SD2's, which can handle 500+ watts a piece and have incredible output. The seats still flip and fold flat, and the floor can be built to handle a lot of load weight if need be. Even more than the stock flimsy plyboard actually.
Another box I'm working on is possibly a spare tire well box that
keeps the spare! This design will be something I'll have to work on after I finish the others up, though. The idea would be to put a single 8" or maybe a pair of 6.5" subs to work, in a tiny box that takes up the spare wheel's room, and then just a bit of height above, making a higher floor. Still low enough to flip and fold the seats though.
So the idea of this thread is just to talk about these, and see if any of these rough ideas are of interest to other Flex owners.
Thanks!