Soldier z:
GasGas:
The original air-cooled VWs had an exhaust gas heat exchanger as a demister/heater.If it holed, you had exhaust gas ducted inside the car.
Those pesky Germans just never know when to pack it in.
lol… 
just i small easy tip ,keep your air intake behind the passenger seat clean,not that you have a dirty cab but will draw any bit of paper etc an over heat,only takes a sec to check 
keith
GasGas:
The original air-cooled VWs had an exhaust gas heat exchanger as a demister/heater.If it holed, you had exhaust gas ducted inside the car.
Didn’t a lot of coaches/buses have them also? I can often remember the hot smell of diesel blowing into the bus on school trips 
Back in the 1970s our school transport was a particularly decrepit fleet of Duple Bedfords (anyone remember Bare Reggies and Risk-It as they were known locally).
Smoke pouring from under the engine hood beside the driver was a regular amusement as they climbed steep hills, and sometimes we had to get out and walk because the bus couldn’t make it up the hill laden.