lol
I just watched transporter2 and I almost roflmfao.
In the movie, a door and some wall was bulletproof.
The best cover is as much cover as possible.
A have read that most rifles shoot through one or even two buildings containing several walls. I dont know if this is true.
If you cant hide, you should kneal or drop to the ground to reduce the chances of being hit. But this will probably be your reaction whether you plan on it or not. If you are unarmed, ryao. Just a guess.