adywan said:
I did mention that many of the shots in the trailer either didn't have some FX layers enabled to save rendering time or were unfinished. the trench being one of them.

Finished trench:

wonderful :-)

That is a huge improvement, but (don't you hate that word), unless I'm seeing this wrong, shouldn't there be less shadow on the turret? Judging by the snow the sun should be somewhere left of your (the viewer's) head. Yet here the background's sun is still behind the turret instead of in front, though this time on the correct (left) side.