I’ve got a sort of a cop firearm training video which goes into some of the differences between common/normal firearm categories. One thing they mention is that cops and govt. agents dealing with terrorists frequently end up having to try to shoot them through car doors as they try to escape and that of all the firearm ammo which is normal or common, the first thing which will PREDICTABLY go through a car door and then either kill or seriously injure somebody behind it is the 308. Apparently a 223 won’t do that predictably and neither will a 44 magnum.
I can tell your from trial and err shooting that a 5.56mm FMJ will usually go through a car door. If it hits two or more “heavier†pieces chances are it won’y. A 308 will almost always go through but i have had some fail if they are off angle. A 44 - haven’t tried that but I suspect it could be stopped by the heavier stuff.