Going to the outback in a truck is a little different than going out on foot. You can bring many more supplies, and cover 10 times the ground that you would on foot. But that also means you can be 10 times farther out when something goes wrong or stops your progress. You need to be prepared when heading out into the wild where no one would find you for days at a time. And lucky for us wheelers, we can take so much stuff with us that we could be out for a month before having to turn around if we pack it all right. We thought we'd let you in on some of the basic necessities that we bring when out in places where concrete doesn't grow. There are a lot more items you should pack for yourself to suit your own needs, but every truck should be fitted with at least these following supplies. And yes, this is a good excuse to tell your wife you need another chainsaw. One just to keep in your truck.
Surviving for days at a time means being prepared to eat more than what your intended trip packing provides for. You should have a backup supply of water, gum, nuts, candy (quick sugar rush for energy), and health-food bars in your 4x4. Some dried fruit is good too if you get the type that won't spoil after sitting for months. You should never break into this pack of goodies until it's absolutely necessary. This is not for snacking. This is to be utilized only after all the food you packed in your cooler is gone and you're stuck somewhere and hungry. It's amazing how long you can stay alive on some high-protein nuts, health-food bars, and some candy. Also, having refillable water bottles and microfilters like this can be great if you're near some water. Chemical water-purifying kits are available as well.
You can always shed layers if it gets warm, but if it gets cold, you better have a way to add covering to yourself. Having an extra jacket or sweatshirt in the back should be an automatic, but you should also have a blanket or sleeping bag or both in your truck, in case you're spending some cold nights in the truck. And it might not hurt to have a tarp or a small tent you can use for shelter as well. If something happens to the truck to prevent you from sleeping inside it, then a small shelter could save your life.
A means of communicating with others can often dictate if you're getting help out of the situation you're in, or helping yourself out. Every truck in the outdoors should have a CB, and a cell phone should be stuffed into a glovebox as well. And speaking of electronics, it doesn't hurt to have an AC/DC power inverter with you either.