I've always used seat organizers to hold stuff like binocs, extra film (in the days before digital), batteries, maps, two-way radios, etc...I'm constantly trying to pair down and consolidate gear, and be very organized. There's nothing worse than being on a long stretch of lonely highway at dusk and not being able to quickly (and safely) access the gear you want. I also make it a point that all gear *should* be accessible to both pilot and copilot, and I try to shoot for logical placement.
I like a cargo net mounted high for clothes and hats, to keep them out of the way but easily accessible. I am also a huge fan of Plano tackle boxes to keep small items organized. Any tackle box will work, but Plano in particular offers dozens of different sizes. I just recently found some at Cabela's that fit snugly in the long skinny compartment of the cargo area of the 100 series (copilot side on a LHD vehicle), two of them lengthwise. Perfect to keep extra bulbs, fuses, relays, connectors, ARB mend kit and pin tool, etc. Tackle boxes are cheap and light and can be stacked, kept inside the center console, in the door pockets, in the glovebox. If carefully packed, they won't rattle and it's easy to customize the compartments or even cut out the fixed ones to adapt to your needs. Some of them are even waterproof.
Editor, South & Central America
'99 UZJ100 Toyota Land Cruiser