My assumption is that Aussies have garages that they keep their cars in. The average home is drastically younger in Australia than in Europe. Plus the sun will absolutely destroy your car in tropical/sub-tropical/desert climates, and getting into a car that has been roasting in the 40C sun all day is honestly worse than getting in a car that’s been sitting in -10C overnight.
More cars inside buildings which have other sources of fire? I suspect more in Australia are kept outside away from flammable things.
My assumption is that Aussies have garages that they keep their cars in. The average home is drastically younger in Australia than in Europe. Plus the sun will absolutely destroy your car in tropical/sub-tropical/desert climates, and getting into a car that has been roasting in the 40C sun all day is honestly worse than getting in a car that’s been sitting in -10C overnight.