Wow, I learned to drive a stick on that car around 1966. It was our second family car (first time Dad had ever bought a second car).
All these years I’ve been under the impression the heat came from the air blown over the cylinder fins! Thanks for setting me straight on that. Nothing like over 50 years of misapprehension!
I drove that bug onto a shallow frozen pond and heard the ice starting to crack! Luckily I was able to get off before it fell in. Stupid teenager!
If I hadn’t had to work on VWs and airplanes... I would never have suspected that they would design heaters that relied on exhaust gasses to heat their cabins. Seems and often is dangerous. I have some stories but will not bore people with them at this time.