imagine, you have an accident by the side, the car catches fire, your door is blocked, the glass has resisted, super !!! And now how do you get out of your car on fire ??? oh yes you will go out (by the morgue) like a saussice too burned.
And if you live in Florida or in a country with the sea next, you find yourself drowned without being able to break the windows.
In Europe, armored cars are not insured for people inside, they are only insured for outsiders for the damage you do to others. Because you put yourself even in danger by increasing the resistance of your vehicle, which is not recognized by the road safety oragnismes.
Same for the horn, in Europe it's forbidden.