Where are the three microphones? It looks like they might be in the left speaker grille, to the left of the keyboard. If I get at a certain angle with the light I can see three off shaped little things inside the grille.
I saw the iFixit breakdown, I didn't see anything that showed the microphone location. Thanks @Cryates , that seems to be where mine are - here is a picture I took, it's not that good as they are hard to see but you can see one of them - the other two are above the circled one.