That's a little design I cooked up with the help of an earlier post NotSoSimple made with pics of their stock trooper.
I didn't use solid diagrams, so you will notice some variance in the dimensions regarding the wheelwells. They may be completely incorrect but the overall layout is sound.
Please excuse the cruddyness. I am not an engineer (although I would like to be) and I am not familiar with the "right" way to do schematics. Never really learned how.
1 and 2 are the points where the cross sections are. The rest should be intuitive.
In this case I'm assuming the storage unit is used with the seat folded up- it could be sized to work with the seat down, eliminating the C areas (and the question of how to reach them). Also, I am not occupying space directly up to the doors- I'm leaving 3-4" of dead space before the doors, just because it seems like a good idea. You can sort of see this in the picture I pasted in with lines drawn on it.
A is a sliding drawer. This is the best solution for the space up to the tops of the wheel wells. It pulls out the back on supporting steel rails. I've seen similar truck drawer designs, that was my inspiration here. Since the wheelwells create pockets, the areas D1 and D2 can be lockboxes. A could also be two drawers, with one 2/3 the width of A, the other 1/3 the width of A. This would let you pull out one of the drawers with just the one trooper door open.
B, I do not know what to do with. For the area above the drawers and boxes, it could be anything. I would like something that folds from horizontal to vertical in two sections divided down the middle (length of vehicle) like clamshell doors. You could really do anything with this part, maybe more sliding / opening sections.
C is the problematic area. Again, if this were made for use with the rear seat in use, C is not a factor. If A extends all the way as far as it can (for an extra long pull out drawer, the end of the drawer would have a little drop down leg that would support the weight outside the vehicle), then you have the two little spaces C1 and C2, similar to D1 and D2, but not as easy to reach. Maybe a pair of subwoofers could go there.
D1 and D2 as lockboxes would be the perfect size for handguns, cd players, cameras, etc.
If A stops at the end of the wheelwells, then C is a single section. It would be kind of hard to get into, though. If B stopped where A stops (in the same sense) then C could go up into the same area where B was (am I making sense) and just be a sort of bin to dump stuff in from the front seats.
That's all for now.