I haven't seen it mentioned anywhere so i want to share this with everyone. I credit bOnEs for figuring out the general location, and DuPz0r (myself) for finding these interior locations in the main map. If we are not the first to find then please correct me, but as i said, we found these ourselves.
MC Meth Lab
MC Weed Farm
MC Print Press
MC Coke Lab
MC Forged Doc Press
CEO Import/Export Warehouse
Images of some of these locations:
I've also managed to make Deathmatches in them if anyone is interested (PS4).
Very very awesome, I was worried this thread was dead