I was just about to post and ask about the vent line to the cable box when I found this thread. I too had placed bellows on most of my vent lines until I read about Joeym33's bellow failure. I had ran mine for a couple hundred miles without any issues but one failure scared me enough to pull them. That brings me back to this box. I can't hardly believe that little line moves enough air to remove moisture accumulation and it sure can't be a drain as it runs upward. Seems like a perfect place for a bellow? Thoughts?