Vehicles equipped with a dozer blade may re-roll a failed Difficult Terrain test as long as they are not moving over 6" that turn.
It is not uncommon for vehicle crews to add additional armour plating to their vehicle to provide a little extra protection. Vehicles equipped with extra armour count 'crew stunned' results on the Damage tables as a 'crew shaken' result instead.
The vehicle has mounted upon it a suitably large and impressive symbol of the Ecclesiarchy. Loyal servants of the Emperor will do their utmost to protect this icon from desecration by the enemy.
If the vehicle is assaulted, any friendly unit with a model within 6" of the vehicle may make an immediate assault move if this will take them into contact with the assaulting enemy unit. Both sides will count as charging, and therefore will benefit from the +1 Attack charging bonus and any other special rules. Enemy models in base contact with the vehicle may still allocate attacks against the vehicle, even if they are in base contact with a Ministorum model.
A common additional weapon system for Imperial vehicles is an anti-tank missile, often called a hunter-killer. This is treated as a krak missile with unlimited range; roll to hit as normal. A hunter-killer may be fired only once per battle.
Pintle-mounted storm bolters are located on the outside of a vehicle. They can be used by a crew member from an open hatch or remotely from within the vehicle. They are treated as an extra storm bolter, which may be used in addition to any other weapons the vehicle may fire. Note that this means that a vehicle that moves can fire one weapon and the pintle-mounted storm bolter. If the vehicle would not normally be allowed to fire any weapons (because of the distance it travelled or damage suffered, for example) then the pintle-mounted storm bolter cannot be fired either.
These are only of any use in missions where the rules for night fighting are being used, such as the Night Fight mission. They allow one enemy unit spotted by the vehicle to be fired at by any other Sisters of Battle units that are in range and have a line of fire (the enemy unit has been illuminated by the searchlight of the vehicle). However, a vehicle that uses a searchlight can be fired at by any enemy units in their next turn - they can see the searchlight shining out in the dark.
Some vehicles have small launchers mounted onto them that carry smoke charges. These are fired off to temporarily hide the vehicle behind concealing clouds of smoke, and are most often used when it is moving in the open.
Once per game, after completing its movement, a vehicle with smoke launchers can trigger them (it doesn't matter how far it moved). Place some cotton wool around the vehicle to show that it is concealed by smoke.
The vehicle may not fire in the same turn as it used its smoke launchers, but any penetrating hits scored by the enemy in their next Shooting phase count as glancing hits. After the enemy's turn, the smoke disperses with no effect.