Ok, currently my local game guru and I have been arguing over how targetting selection works if a large target such as a Monstrous Creature, or a Vehicle is closer than another unit.
Now according to my reading of the rules on page 19, if a normal unit such as your infantry are closer to an enemy unit than one of your vehicles, he can decide to shoot at the vehicle instead without a morale check. . .
However the opposite is not true, if you have a vehicle closer to his unit he would have to make a morale check to not fire at your vehicle, even if he was unable to damage it. . .
This came up when someone had multiple Devilfish in front of their Fire Warriors, and kept forcing a Marine scout squad with a heavy bolter to fire at the Devilfish because of failed morale checks?