Smoked cigs, back-when..... missed the little triangle/butterfly front windows, when they went away.....Defrost on full works ok if you can handle the heat so I rolled down a window I kept the windows cracked or down anyway in my chain smoking yrs lol
Trucks not so much (actual workers-in-trucks had no sense of humour here, about lacking heat), but cars got really stupid, with low-drag water pumps. First time I really noticed, was test driving a Pontiac for my buddy (his repair shop, he wanted it driven) for something else, V6 - I said ****-poor heat on that thing, he explained those v6 are all like that, low-drag Wpump, so next to no flow up through the heater-core. I said - "let me get this straight - to save fuel on the Wpump drag, I'd have to idle the engine @ something like 3k rpm, crawling back home on a long commute in an ice-storm ? Yep, was his answer. Progress.
(Later, 12v booster pumps got added to the Heater Core loop, various manuf cars, to deal with this ^).
Rgds, D.