Side Air Bag Module
WARNING: This page does not describe the selected car, but rather 9 other vehicles, including the 2000 BMW Z3, 2000 BMW 328i, 2000 BMW 323i, 1999 BMW Z3, and 1999 BMW M3. However, it is still accessible from the selected car via links, so may be relevant.
Side air bag modules are installed behind door trim panel on both front doors. They are accessible by removing door trim panel of appropriate door. Side air bag module consists of an inflatable air bag, gas generator, and igniter. Air bag fully inflates in about 35 milliseconds. Gas is then released through a filtered vent on the back side of the air bag, causing it to deflate.