.
Whatever you have will
not be rated high enough if you are sitting behind that door and something hot is coming your way! I personally have never been on the
"shot at side" of a door before. Hope I never get to have that experience in the future either!
On the other hand, reading the ratings for
"bullet resistant panels" seems really low and not nearly enough protection if you are on the receiving end. Add in an armor piercing projectile and the numbers for survivability drop off pretty quickly. I would guess that a .308 round would come right on in, and a .50 BMG will go through both sides of the truck. NO Protection is definitely worse than whatever numbers you might be able to find. Obviously a shot fired at an angle has a better chance of being deflected...
Planning ahead like you are doing and personal body armor on top of that is better than a lot of people have. Hopefully it works better than advertised and if the need arises you will have plenty of something to offer in return