Well actually we pulled the back seat out of the Navara made up a frame and put a couple of big plastic boxes in to keep our clothes out of the dust and the most important thing we took on the trip.
A 60L Evakool fibreglass esky.
That was always full of beer and ice when we could buy it. When we were away from ice supplies we would freeze a special bag in the freezer compartment in the Engel(fridge freezer) and then pop it in with the beers and we'd get around 3 to 4 days out of the ice. Then we'd be in some place and could buy ice. At the NPA (northern peninsula area or No Proper Alcohol by the locals) you had to be careful as you were only permitted to have 9L of mid strength and 2 casks of white and red wine. So you had to drink the grog before you bought a new slab.
Some of our guys had to bury a carton of Johnny Walker and a carton of heavy in the bush. The secret to digging up the buried tresure is to dig a hole behind a big ant hill(some are over 3m high) and when you fill it back in leave a bit of sh!t paper hanging out of the hole.
The locals up there are renouned for doing a little treasure hunting, so a fresh hole is gold to them seeing they can't buy heavy beer or spirits. Silly thing about it, is on origin night was drinking rum with the managers of Loyalty beach fishing lodge and if go into the Bamaga tavern you can buy and drink anything you want, you just can't take it away.