So what about the ol' reliable 12 guage shotgun?
Well, we played with that too, using both buckshot and slugs.
Again, notice that I captured the weapon cycling...
Let's take a look at the door.
Yet another one.
And the result?
The buckshot essentially performed like several slow 9mm rounds, penetrating a single door, but being stopped somewhere in the passenger.
The slugs penetrated completely or buried themselves deep in the passenger door.
A car door doesn't protect you against shotguns either.