cold air entering the cargo area

I thought I had read here (can’t find it now), about plugging the areas that let cold air enter behind the seats. During summer it is welcome to have the added ventilation but in winter the puppy in the baggage compartment complains. We use blankets but I was wondering if anyone has found a simple “put foam rubber block here” solution, and where is “here”?

draft

depending on how tight your wing root seal is, I suppose most of the draft comes from the insert the wing enters the fuse. My plane is stuffed with some foam over there, problem solved.

My solution - -

https://vansairforce.net/community/showthread.php?t=64145&page=21

Can see thru it. Easy to remove. I leave in year around.