Just an FYI...the default for the SRS/MRS system is that ALL airbags deploy even when they aren't supposed to.
So the thing to do if your front passenger occupancy mat sensor is the reason for the light in the headliner being illuminated...always have the passenger in that seat where their seat belt. That way, if you are involved in an accident...the seat belt will keep the person in place...because the air bags may deploy when in normal circumstances they would not.
See the info below as to how the dual stage SRS/MRS is designed to react when passengers are belted and the bags deploy...or if they aren't belted:
"normal response range" would be for the front pass air bag NOT to deploy if no one is sitting in the seat...but if the air bag light is on...then the bag may deploy when it's not supposed to. BMW designed the system to default to the side of safety vs the liability of a bag NOT deploying when it should have...and an occupant is injured/maimed/fatally wounded:
(take note of text highlighted in the green & yellow in image below...it explains again, that the default is for the bags to DEPLOY...even when they aren't supposed to when the SRS/MRS (supplemental restraint system/multiple restraint system) light is illuminated)
