In fact, as far as cars are concerned, all works as if fire geometry is insensitive to primary weapons/ HMG projectiles.

Firing at a whatever car (from hatchback to HEMTT) with common BlueFor guns will lead to damage = 0 until the car is destroyed (damage = 1). No progressiveness except for minimum 7.62 cal (Zaphir) on a hatchback. This case is slightly responsive for damage count.
The results for damage status (between 0 and 1) are something like this:

• quads react (means !=0) for 6.5 cal (good news), but not hatchbacks! (shifting from 0 to 1 when exploding);

_ offroads keep damage at 0 with a 7.62. but are quickly destroyed. Hatchbacks take progressive damage (until about 0.2 then shift to 1) but seem to be more difficult to explode than offroads!

Take a .50 HMG and fire at Hunter or whatever military car IFRIT STRIDER HEMTT! There is no damage status else than 0 until you explode it.

Deep silence about this post.