Our Mooney M20E doesn't have headrests.
I have to admit that, on longer flights, my wife and I find it pretty exhausting to just sit still for hours, without being able to rest our heads against something. We are both pilots, it would also be great if the non-flying person could move the seat back and rest comfortably.
We thought about adding headrests. From what I read, however, the original headsets aren't really effective.
So, how do you make yourself and your passenger comfortable on long flights?