No, the heat exchangers were fine, the design just sucked. I had seen aftermarket electric fan boosters to try and push more air through the vent pipes and help things. I mean, it had a long way to go! But even the squirrel cage fan in the blower assembly in the truck wasn’t all that big or strong, so the air it pushed up onto the window was far too little to do much. I loved my Beetle though, despite all its issues.