No, I only have the clamp and it doesn't work anywhere. I already went up to the roof looking for doors or some item. There's the air vent, the women's bathroom, glue machine, trash can and this other door where I don't know what to do to progress. I believe I may have a bug.
Just tested it out myself and I can't spot anything obvious that's wrong...the door round the side should open by itself at this point.
I will keep looking to see where the problem is, but for now I have just finished a bunch of optimizing and uploaded the updated file.
Might be worth downloading the new one and seeing if it's any better.