Vehicle Security is a great topic, one often ignored during expeditions, sometimes with drastic consequences. A few years ago a couple of TLCA members were surfing off a remote beach in Baja California, and when they returned, they found their Land Cruiser gone, along with all of their equipment.
Being originally from Venezuela, my Land Cruiser is equipped with what was state-of-the-art security in 1990 and remains overkill for most US applications. Most of the security devices listed below are mechanical in nature because of the intended use of my Land Cruiser. None are completely theft-proof, but are designed to complement each other and simply make the vehicle as least attractive to thieves as possible. This isn't to say that the truck can't be stolen, simply that it's going to be much easier to steal the next truck than mine. Among these are:
1. Shifter Lock + Shifter Collar. This device manually locks the shifter in reverse and prevents the shifter from being pulled out or removed.
2. T-Case Lock: works in conjunction with the above (single key) and manually locks the t-case shifter in low gear.
3. Pedal Lock: Locks the brake and clutch pedals together and prevents them from being depressed.
4. Fuel Cutoff/Anti-Carjack: Mechanical device located on the floorboard (under the firewall), allows cutting off fuel supply
5. Hood Lock: A low tech section of re-inforced steel chain that drops in front of the radiator and locks to a welded tab on the frame.
6. Two separate electrical cutoff switches
I don't have pictures here in the office but I'll post some tonite.
On expeditions in remote areas, VISIBILITY is what usually gets us in trouble. If people can't see your gear, they'll be less prone to grab it, even if they assume that you have it. Thus, it's always important to have gear stowed/out of site when you park for fuel, and especially important to keep gear stowed away when you're camping and out for the night. You might *think* you're remote and miles from anyone else, but I've had stuff stolen from our campsites in South America in very remote areas, nothing is ever really safe. Most of the time it's a crime of opportunity rather than one being actively targeted.
I second the notion of securing jacks and spare tires and suggest taking it a step further. When on expedition I run a cable through the handles of all my jerry cans, not only while they're on the rack, but also when they're on the ground. The cable is long enough that I can run it through either the trailer's wheel or through the legs of chairs/tables and cooler handles. In some areas, this isn't necessary, in other places, it's the only way of keeping stuff around. Again, this may not deter a dedicated thief, but will keep crimes of opportunity at a minimum.
On my trailer, I padlock the steel lid (which prevents the tailgate from dropping) and keep a lock on the lunette hitch when the trailer is not connected to the Cruiser. Even when they'e connected, I run another cable from the trailer's tongue to the Land Cruiser's rear bumper.
Great topic!