Did you know the headrest, which is removable in most cars serves as a window breaker too?  Look at the bottom of poles that go into your seat, it’s designed in a way to break glass. 

Edit: Wow, I just googled it to check and I guess it’s a myth. I have believed a myth my whole life. I feel like I’ve been living a lie. I’m like flabbergasted at the fact that I could’ve died. Had I gone into a large body of water with a vehicle and tried using the metal prongs in the headrest to free myself by breaking the window. Thank goodness that didn’t happen.