I just posted this reply in another thread, but I'm curious if anyone has also encountered this issue after a few years of mbp ownership? On the current non-retina mbp and older 2008-11 mbp's, high exhaust fan heat generated by running the fans on high with the lid closed over many years can actually mess up the plastic clutch cover over time. I have a mid 2009 mbp that I use to play games in bootcamp in clamshell mode a lot of the time over the past 3 years. The result: right where the fans exhaust in the middle of the screen I started to get some cracking in the black plastic clutch cover. I've only ever seen this reported in one other place on the net: http://www.resourcesforlife.com/docs/item3485 My clutch cover was replaced under applecare due to this cracking, but I know this was due to heat exhaust and not pressure. Those of us using the older style mbp in clamshell mode with the fans on high for hours on end every day would do well to run in clamshell mode but also lift up the laptop screen so that it's open a bit when playing games in bootcamp. This is pretty easy to do. You just have to remember to bootup in bootcamp with the screen closed, and then lift the lid afterwards. Less heat hits the plastic clutch cover if the screen is open slightly. I wouldn't call this a defect as plastic will do this if exposed to high temperatures over time. I just think the materials used for the clutch cover should be upgraded to prevent this in the future. Of course, I doubt most users are running their mbp's in clamshell mode all the time with the fans spinning on high for long sessions.