Thanks for all the input.
I'm almost done w/ this build, I brought a shallow mount 10" since i want the lowest floor/lockbox possible.. in the process of the final insall of a custom lockbox/sub enclosure and fake floor, the 2 amps are also completely hidden. Will post a some pics when done, need to just figure out the cam lock and bolt it all in... Using stock head unit, 2 amps 1 sub, stock speakers(for now). Want a total stock looking system since my top and doors are always off....

 

So..... after seeing ronjenx's build of his thread "under-floor storage" I knew I wanted to build one for my rig, ESP since the wife wants a place to lock up stuff when where at the beach or whatever, and I want to have a better stereo since I'm a musician.

I modified ronjenx's design to fit my needs. Used mdf and 3/4 ply for the lid, going to make the 2 boards that make the hole back be flat when the seats fold down but will not be on a hinge thus way I can just use them when I need them, my box is .75" taller that ronjenx's box.

Here's the "almost" finished product..just need to bolt it down, install the lock, trim the extra carpetbthat covers the jack.
Btw, the sub is concealed under the back 1/4 of the lock box, I'll take some better pics when I go bolt it in...