Australians love their cars, I think I have mentioned that before [Observations: Distance & Size], but I have not yet mentioned how many cars are 4 Wheel Drive. From a newspaper article I recollect that the percentage of 4WDs sold in Western Australia is about 20%. However, the majority of the population lives in metropolitan Perth and has less need for a 4WD, so that is why 2WD vehicles are still sold most. But as soon as I travelled north of Geraldton, it seemed that at least 50% of the cars was 4WD.
Australians use their 4WDs mainly on sealed roads, but there are quite a few 4WD-only roads in National Parks, and a 4WD is virtually necessary to launch a boat from the beach (very popular) or tow a caravan (less than 10% of caravans seemed to be towed by 2WD, as if you are not supposed to do that). It would also be necessary to have a 4WD when driving in the north during the Wet, since you would have cross many rivers and streams, even on the sealed roads and highways. For that purpose some 4WDs are equiped with a snorkel (‘elephant cars’ as I prefer to call them), so they can drive through deeper water.
Nevertheless, most roads can be driven in a 2WD, although it takes some getting used to for Europeans like me (I mean, even roads on campsites are sealed in Europe, a fairly unknown concept here). And you can stay on sealed roads for a very long time in Australia, but all the off-the-beaten-track destinations are only reachable on an unsealed road. Not that strange, considering a lot of the Shires outside metropolitan Perth have up to 3 times more unsealed roads than they have sealed roads.
In any case, I will probably not drive much on 4WD-only roads in my own 4WD, but it is good to have the extra security of 4WD on unsealed roads, especially when the road or the weather is bad. And I do plan to take the Gibb River Road throught the Kimberley, which is a 700km unsealed road through the heart of the Kimberley. But even on that road the plan is to keep my car in 2WD, following Western Australian wisdom: “if you get bogged in 2WD, you can get out in 4WD, but if you get bogged in 4WD, you’re f**ked”.