With the cold weather we've been having in the Seattle area it has made it uncomfortable flying as my heat system doesn't supply enough of the warm stuff. I have been trying to plug all the holes where the cold air is coming in but it hasn't helped much. I decided that if I can't keep the air from coming in I would try to keep it from going out, there is a lot of air flow out along the canopy rail, so much that in the summer my shirt sleeve gets sucked out. So, on Thursday before our lunch outing, see related post "We fly for food", I tired an experiment, I hung a "curtain" along the canopy rail to slow the flow of air out of the airplane.
This was a temporary setup, it is made from "duck cloth" a light canvas type of material and held in place with tape. The results, we were very comfortable on this trip even with OAT of 30 deg F. My wife, who is always cold, said it made a big difference, I would call this one a success. Now to make it "pretty" and easily removable for the summer, I like all of the air flow in the summer.