I have a heavy serrated folder with the glass breaker tip protruding from the handle's end always at hand in the car, clipped to the DIY cutout in the side of the belt's well (along the car's side beam) and also attached to it with a short lanyard. That piece of the frame seems to have an equal chance of surviving in the crash as myself.
Don't know what you drive. Do make sure it will not interfere with the side and window airbags and the seatbelt pretensioner and loadlimiter (not sure what the belt well is). Also note. that the the side and windows airbags will cover the B-pilar (window airbags generally go fron the A to C pillar.) You will need to push those away. The window airbag is design to stay inflated much longer then the front airbag, as it has to protect you for longer during a roll over and i prevents bodyparts from sticking out during a roll over.
Okay, so pressing the tool into the window compresses the spring with trips and breaks the glass.
For succes at first try, swing a spring tool too. When I just put a ResQme on the glass and gently start pushing I need 2 - 3 tries. If just hold it in my hands and ram the glass with the punch, i have had instant succes.