I replaced a couple of VW heater boxes in the ca 1980 (because they would rust out in VT and there was a market in Texas heater boxes). Those vehicles had air-cooled engines and the "heater boxes" came off the engine (maybe took in rerouted exahust???) and then had ports in the car. They were fully passive. No fans. If the engine got really hot, you could cook eggs on the floor of the back seat. But until the engine got really hot and the heater boxes got really hot and a sort of chimney/convection thing got going, there was basically no heat. No A/C of course. But almost no cars in VT had A/C then.
I trust that 50 years of tech advances will come up with something better. In any case, an electric motor requires that it at least be different.