My 15" tMBP has just started making a rattling noise when moving the device from side to side. I had two replaced soon after my initial purchase, one for a rattling case (by the trackpad, which this current one still suffers from) and one for popping keys (which this one has also started doing, 6 months in). From an audible point of view, this MBP is aesthetically the worst I have ever owned.