After my flight instructor complained about getting cold sitting next to the door, we put a new door seal on yesterday.   The old, leaky HD door seal was installed a few years ago by that same instructor, but that is another matter... In the process we took the door interior door liner off to avoid messing it up any more than it's 50+ year old self is already messed up.   Look what we discovered inside the door!   This huge mud-dobber nest (how did they get in there???) weighs about 1/3 of a