Canada has automotive manufacturing. Charger and Challenger in Bramalea, Honda in Alliston, GM in Oshawa, Ford engines in Windsor, Stellantis vans and I believe EVs soon in Windsor, Brightdrop EV cargo vans for GM in Ingersoll, Toyota and Lexus in Cambridge and Woodstock… and I fail to see what that has to do with anything .
Now what manufacturing does Australia have? None. So they have no reason to erect tariffs. Thus it's an entirely free market, where Chinese EVs can prosper, exactly what is not happening in the US.