Hi All:
A few minor mods I did last summer was in the cargo area of my FJ40.
The first thing I did was mount a $25 plastic storage box (from Loew's) to the floor right behind the front seats. Now I don't have to worry as much about my tool box "disappearing" from the truck!
Another item was to "install" (very loose use of the word!) a rubber mat on the cargo floor to protect the paint and cut-down on rattles and squeeks. This is one of those mats that are used on the floors of restaurant kitchens - it is thick and tough and cost $20 at Home Depot.
Finally, I used a five foot piece of pre-perforated angle iron to make a pair of tie-down rails that I bolted to the tops of the wheel wells.
See the below photo for more info.
Regards,
Alan