[rosnd]

My gas powered Mercedes heats up just fine without starting the engine.

This has been a common feature for like ... idk, 20 years? I think even the 80s W214 had this option, although that used a separate burner system instead of batteries.

[rvba]

You are getting downvoted, while you write the truth.

High end cars had that feature for years. Lower end ones used various block heaters / car heater boxes / webastos.

[thesmok]

It still burns fuel and exhausts CO2 doing that.