[nuccy]

VW diesel cars can be equipped with Webasto (auxiliary heater which burns diesel). One gets a remote (in my experience reaching up to 500 meters) which can be used to start this heater along with car's climate control. The advantage is that it consumes 1/3-1/5 of what an idling engine does, while heating interior and engine coolant much faster. The disadvantage is that it consumes battery charge, but to counteract that the car is equiped with 30-50% bigger battery. Though this was never a problem for me, from my experience on 94Ah battery it can run for hours without any effect on engine starting, while heating the car in some 10-15 minutes when it is below freezing outside.

[gambiting]

So in my Volvo XC60 T8, the car just came with a Webasto preinstalled from factory, it was standard fit on all models(in 2020 in UK anyway). But you can only start it from the app, they don't give you a separate fob like the one you can buy from Webasto, so you have to pay Volvo's subscription to use it.

[baq]

and, in the models that use the engine coolant as a working fluid, your engine is heated up to a cozy operating temperature right from the start, so you end up about even on fuel.