I manage to capture it today (redirect to Youtube) It started a couple of days ago, only when I move my laptop and it lasts about 5 seconds. What could it be ? I really don't think it's the "speaker pop sound" problem which affects other rMBP's. Sometimes the rattling is coming from the top right side, sometimes from the bottom right side. It's like something is moving in there, and like I said before, it appears only when I move my laptop. I have only 3 weeks left of warranty. 15" Macbook Pro with Retina Display, Late 2013.