I think the clue is here "it takes 49.48 percent of a person’s average yearly salary to own and operate a vehicle". Aussies, on average, make good wages. Consequently the cost of owning a car is a smaller proportion of their income. The actual cost I suspect is much more. For example, the Leaf e+ cost starts at AUD64,990 (USD47,440). Not many states or territories offer rebates on EV's. Petrol is more than the US. Buying a coffee is much more. The minimum wage is around AUD20 (approx USD15). They get 4 weeks of holidays. I lived there for 26 years and never thought owning a car was cheaper than my home country of Canada.
Yes, this study based TCO against average annual salary. I was surprised how high EU countries were. I thought salaries were pretty high there too. I know fuel costs are high. Here in Canada, our fuel costs are high, too.