Probably parked indoors, as well. My low-mile '81 has very good weatherstripping as well. Came from Wisconsin. I think indoors, as well as a mild climate, help. Heat is bad. Did you notice what he did to the lower side molding?
I imagined myself sitting behind the wheel and I was just waiting to hear Captain Picard say "Engage" Its yyour own privet Enterprise! ... I'm such a nerd...