found an emerald but not really sure whats its for :P

Trying to find the last few emeralds, and there's some things I haven't figured out yet. 1 - does leaving the nuke do anything your second time around 2 - is there a way to spin the wheel in IQ test room 3 - is there a way to get through the Fire Door? There's a water cooler and a goblet nearby but you cant interact with either 4 - any way to get to the platform behind the start in Dr Chair's last level? Also, if anyone knows where the flying cars are for the "You Found Your Way" achieve, I have no idea...

Does anyone have any info about the Colours emerald? I am completely out of ideas and cannot for the life of me think of anything that hints at it anywhere in the game.

noclip at room where you deposit weapons (first room after elevator), to the right of that crate you can jump on plant and on to the window, jumping at wall from it (the top of the wall has no collision all around). From there you can see two emeralds. red and green (normally can be seen in maintenance closet atomic blast room at right edge). the red one you get by doing the puzzle with club heart doors and then going to lighthouse top or maybe its the other red one the one fro...

I was able to fairly easily get upon the fence on the left-hand side of the final room. After triggering the dialogue (which didn't appear to have subtitles, adding to it being an ad hoc recording, but still worth pointing out) I wandered around a bit and fell into one of the pits at the back of the room, specifically behind the audience box. I could not get out of the pit and no dialogue was playing after a while so I restarted the DLC. It was quick enough to get back to the end and fall into the correct...