Check out the tie-down loops near the seat backs. The floor looks stock height.
It looks sharp. Nice imagination & work. I'd be a little concerned about the strength of the floor (i.e., how well it's braced against the spare tire) if you haul a lot of heavy stuff around. Othwerwise, very cool.
And the plexi is a nice touch too.
i would think the sub would be at the back and not near the seat?? especially with how a subwoofer corner loads inside of a vehicle??
My bet is it would hit deeper and increase in loudness a little just from placement.