Hey all, I thought I'd drop a line to help shed some light on the rMBP creaking chassis we sometimes encounter. I've had a 'late 2013' presenting severe creaking. When I say severe I'm not joking at all. It was absolutely terrible around the trackpad area, clicking simply upon resting my hands on it. At the time, I didn't bother and returned the unit for another one. I was fortunate enough to get a good screen and a defect free unit. I read multiple times that some people simply do not feel comfortable exchanging theirs (within the 14-days) since they fear the screen-lottery. A friend of mine got one very similar to the one I exchanged and creaked pretty badly. Picking the laptop up, even by both corners at the same time, resulted in severe clicking noise within. He went to the Genius Bar to get a reset of the bottom plate + screw tightening. Alas, no fix. The 'genius' said it was 'within specs.' I decided to give it a go and opened his bottom plate with my pentalobe screwdriver and this is what I found which makes you wonder whether or not Apple did really open it or simply tightened the screws. The battery pack was covered with various sized aluminum residues/bits from the unibody machining. I actually thought this was rather odd knowing how OCD they are about what it looks like inside. Let's not even mention what such bits could do if stuck in a fan. The culprit seems to actually be around where the bottom plate sits. Some aluminum bits where stuck in the rather narrow groove that makes contact with the bottom plate. I took a small paint brush to 'clean' the groove and removed all the residues sitting around the battery pack. I also made sure the bottom plate received the same treatment before putting everything back together. Don't forget that screws are different and have to go back in the right holes do not mix them. Rock solid. No click, no creak anymore. It's been almost a month at this point and he told me it's been silent ever since. It actually makes sense to me. Since everything is so 'perfectly' adjusted, tolerance for error is rather low. If a very small metal particle gets caught in a groove nearly the size of a hairline, the whole assembly is now off. Also, by being 'off', the little springs around the logic board are more audible since they no longer make contact where they're supposed to on the designated areas of the bottom plate. I agree that at $2.5K it certainly shouldn't be my job to fix what the genius couldn't, but since it's a relatively easy thing to do, I'd take that any day of the week over dealing with their sometimes very condescending associates. In the end, if your unit exhibits bad creaking, I'm pretty sure it's 'dirty' inside and needs a bit of detailing. Hope this helps!