which one

even 25 year Kelisa got

Conti car mostly have heater function. Not all, but most.
Especially the Merc in the diagram should have that heater function.

But Localized car has it for cool air to the windscreen which is useless

I mention B40 nowadays, not  B40 of yesteryears

And it's a Proton Saga.

When raining my colik tumpang me, and I select Aircon shot at the leg, she was surprised. She says her Proton Saga no this function