Of course there are some cars which do have a resistive heating, but which are those?

> heat pumping through AC

Uhm, the compressor runs from the engine so while the heat is not from it, it's still directly relies on availability of running engine.

Also don't forget that seat heaters are also resistive and most cars in cold climates have them.

I know it (or more like my bum) too damn well, though I didn't think about them in this case.

> small diesels like VW Polo

Makes sense, though as I understood, it's strictly auxiliary till the engine is heated aaaand maybe some additional heating at the parking lot with the engine turned off, though I would wary of this usage, it would drain even the extended battery fast.

Overall it's not quite what I had in my mind (think of space heaters), though yes, there are some parts which can operate independently from the engine, though it's not a primary function for them.

Thanks for the hint.