Well, alrighty then. I've given the tool kit some thought over the last few days and I have to say that I'm having some issues with this post. Being a pretty practical guy, and not wanting to drag a bunch of crap around that I don't use, I started to give a lot of thought to what I really needed in a tool kit that lives in MY rig when I go off road. Now please understand, I'm not a SoCal rock crawler or a Georgia mudder. I'm not up to my hubs in mud or jumping ledges and climbing waterfalls. I run the backwoods on Forest Service / BLM "roads", motor down skidder trails and tool down the beach to clam beds and fishing spots. My TJ isn't a fast mover, what with the four angry squirrels and all. My Dana 35 hasn't exploded yet.
With all of that being said, it has occurred to me that I haven't used any tools off road in probably ten years or so. It's blasphemy, but true. I haven't fouled out a spark plug since fuel injection and computerized engine management. I haven't replaced a water pump in the woods or anything else for that matter in forever. I do all of my maintenance at home in the comfort of my own garage with access to a well stocked auto parts store. I don't carry spare radiators, spark plugs, gear oil, axles, or anything of the sort. Once a month or so I go over the Jeep(s) (and the other rigs) to make sure that there are no maintenance or repair issues that will bite me in the butt out in the boonies. I carry fuses, and light bulbs, a multi tool, a couple of screw drivers and the Torx driver to adjust my drivers side head lamp. A 13mm box open end wrench for changing out the soft top. A quart of engine oil and water for me or the TJ as required. Duct tape and rebar tie wire. I'm sure there is the remnants of a roll of electrical tape in there someplace, but I have no idea where at the moment. I have an air compressor and tools to change out a tire, though I keep an eye on my tires and haven't needed to change one out on one of my rigs in years.
Now I know guys who have everything from a complete mechanics kit to welders and receiver mounted vices in their rigs. And use them on occasion. They drive over and through stuff that I drive around. Most of the time it's an injudicious use of the skinny pedal or an error in judgement that leads to the breakdown and causes the deployment of all those fine tools and spare parts. Not always though. As often as not the unplanned disassembly is preceded by someone hollering "Hey Ya'll, Watch this!" and is followed by wailing and gnashing of teeth...and a quick run (hours) into town for forgotten tools and replacement parts. That's usually followed by a weekend spent repairing something in the woods in the rain and the snot.
I guess what I'm saying is you need to evaluate your need for tools and base it on what you are really going to use and really going to need.