to contact hooks extending through the windows 150 and 154 from the air bag container module not shown to reduce vibration rattling in a conventional manner on sidewall 126 a single tab like protrusion 140 is shown in fig2 that runs over most of the sidewall length the guide tab 140 is supported by a series of gussets 141 that are anchored to the side wall 126 between window locations the guide tab 140 is located just below the flange 108 and above the windows 150 to form a slot 142 therebetween the slot has a height measured between the guide tab 140 and flange 108 that is approximately equal to the thickness of the edge of the aperture 51 in the instrument panel substrate 50 the guide tab 140 and slot 142 serve to engage the edge of the aperture 51 during insertion of air bag chute 100 therein following the completion of insertion of air bag chute 100 into the aperture 51 the tab 140 functions to retain the air bag chute in aperture 51 other features pertinent to the present invention include the support gussets 160 shown in fig2 and 3 these support gussets are located on the outer sides of both side walls 127 and 129 to provide a degree of rigidity.