Okay so this is my idea for air ducting. I heard people complaining there wasn’t enough air flow to the people in the rear. I also heard people complaining that the air mixture contraption vibrates and makes noise. And I just think all that extra air ducting underneath the panel will get in the way of working on other things. So to the end, I am only routing fresh air to the air vents by the passengers and pilots. Warm air will only come from the defroster or under the panel. I hope by removing the mixer I am creating a more straight flow from outside to the air vents increasing airflow. The first picture was an idea that took far too long to create and later scrapped. I later went with using the sling provided reducer. Embarrassingly I spent about 2 days on the first idea before I chucked it. Fyi, both solutions have sealant on the inside to make sure it is a tight fit.