I am an old man that used to be a vw mechanic. I liked them and drove them for a long time.
Too bad no one ever talked about the heaters, and how to fix them. Before they were all old and rusted out they would work,,, IF you crack a window open. Remember how pleased you were that it was air tight? The heater pulled air past the exhaust, and blew it into the passenger compartment. If it could not get out, it could not get in. Warning. the front floor vents would melt a set of rubber galoshes on the highway.
Lots of happy memories.