Another comment to the OP mentioned a hose from the exhaust being used to apply heat to the windshield. Prior to the adoption of pressurized recirculating engin

Another comment to the OP mentioned a hose from the exhaust being used to apply heat to the windshield. Prior to the adoption of pressurized recirculating engine cooling circa 1930s, which allowed for internal heaters, some automobile manufacturers offered instant heating of a deadly variety: direct metal ports off the exhaust manifold. Often it was a matter of just sliding open a door to get the hot air circulating. What could possibly go wrong? A bit of corrosion, a cracked weld, and suddenly the folks inside got very, very sleepy... EDIT: I just remembered my dad's old VW Beetle had manifold-heat ducts down by the shifter. We had another Type 3 VW that had a gasoline-powered heater mounted in the front compartment just ahead of the passenger front seat. Consumer safety was not their high priority back then, it would seem.