First, you can get one from your own car by popping your hood and pulling it out. Next, you will need to break the porcelain casing around the spark plug (remembering to protect your eyes from shards). Then take a sharp piece of the ceramic and throw it precisely at the window you want broken.
Items like duct tape, blanket, and pillow are tools you can use to break car window glass. The first thing you should do is to cover the whole window using duct tape from one side to the other. This step is essential as it enables you to break the window gently without a sound
Unlike windscreens, window glasses are tempered. Meaning, they are heated up to an elevated temperature and then cooled down rapidly. This induces a varied surface tension at the inner surface and outer surface. Thus they can be broken more easily than the windscreen
Thirdly, place a high-density pillow parallel to the glass and tap slowly with a hammer. The glass will break, and since the duct tape is holding the glass together, it will not fall and make noise. However, if there are small pieces that will fall, the blanket will absorb all the sound.
Breaking the glass will be relatively easy. There is a catch, though. If you use heavy metal to break a glass, you should go around the edge of the glass at its weakest point. Manufacturers assume that in a collision or impact that the center of a windshield or auto glass is the most vulnerable point