I unbuttoned my soldiers in a .50cal Stryker and put a cover are up for the Stryker. I noticed the unbuttoned passengers in the rear facing each other and not back to back looking outboard.
Above you will see the cover arc for armor on the left.
In this image there is no cover arc.
Both Strykers had a cover arc. This Stryker in the image above had a regular cover arc and the passengers also faced each other.
Ok...wierd thing. After I typed the above comments I ALT-Tabbed back into the game to experiment some more, and I could not replicate this. But fortunately I have pictures.