I took my 13" rMBP into the Apple store for the same issue. The genius tried re-torquing the screws for the bottom case and in the process scratched the bottom case. He installed a new bottom case for free, which corrected the creaking issue by the lower left palm rest area. I then asked them to check into an issue I was having with the display sleep timer not functioning correctly. They sent it out to be looked at and in turn scratched the black part of the hinge cover. As a consolation, they gave me a brand new unit as a show of "good faith". They'll look at it for free and correct the issue for you. Good luck!
Yes; my 2012 15" Retina MacBook Pro creaks when you press down around the trackpad. I brought it in to the Genius Bar twice and it has reduced but not eliminated the creaking sound. It makes the machine feel cheap and makes me not want to touch it or move it for fear of hearing that sound.
And the first screen had white stuck pixels in the corner and the replacement screen (Samsung LSN154YL01001) has a yellow tint.
while giving my cMBP for repairs to the AASP there was a guy with a 15inch rMBP he to complained of creaking issues especially while typing, they retorqued screws and it did not go away, they offered to replace either the top/bottom case.