Dead and Back isn't a wargame, but it is likely that the players will encounter many vehicles, and threats to them.
Convergent and Divergent Damage
Some vehicles do not protect the occupants very well, while others do a very good job. For ease of play and reference most vehicles are considered to have animus tracks that are separate - diverge - from that of the occupants. However, there are some things that don't protect the users all that well, and thus add (e.g. converge) the animus tracks with that of the character.
The two most prominent examples of convergent vehicles are motorcycles and powered armor suits. Motorcycles offer little apparent protection from outside threats, while PA is worn and anything that penetrates the carapace is likely to penetrate the user - at least a bit. In both cases, these things are represented by adding a series of boxes to the front of each level on the character's animus track, to absorb damage first. For example, as mid-grade Power suit with eight animus points worn by a character with six animus would appear as:
  O
  O
  O O
  O O
A divergent vehicle like a car or tank will absorb all the hits directed at it before the characters inside take damage, but they may not absorb them very well. At the end of each row on the animus chart, there may be a listed die to roll - for example a fragile car might have a d8 on the first row, a d10 on the next, and a d12 on the third (depleting the fourth destroys it of course). As with any other roll, the only numbers to look for are the top two, and if those come up, something happens. A tank might have die rolls only on the second and third levels, since its just that tough.
Certain anti-tank weapons (or perhaps a new "armor-buster" SA) might alter the die rolled, or add a roll, to represent the ability for the weapon to wreck interior systems, even if destruction isn't outright. (The system as it is now simply won't let you roll enough dice to destroy all sixteen animus of a tank after-all).
I do not yet have an exact chart of what might go wrong with each roll, but the rule of thumb is that there are four things that might happen - a system might shut down (a weapon or sensor), the speed is reduced, handling is impaired, or the crew get thrown around and injured.
Overkill and Vehicles
Its fairly safe to say, that an anti-tank missile is going to ruin a standard car, and devastate a man-sized armor. However, killing players in one shot from a generally unavoidable source may not be very good for the narrative structure of the story the game is portraying. Thus the cinematic thing to do would be to allow the character to survive, but to take injures in their narrow escape or to become trapped in the wreck until they or another find a way to get them out.