It'll be a challenge to have heaters in electric cars as they reduce the mileage. In gasoline engines heat is obviously a byproduct whereas in electrics it drains the battery to get warm. Who knows, maybe they will use propane
heater eventually, e.g. powered by cow farts to be eco friendly, or to be safe smth with a chemical reaction being the source. At any rate given all the resistance from the Big Oil I am genuinely surprised to come across a Smart clone in NA that is built on existing tech and manages to sell nonetheless.