BMW Recalls 200,000 Vehicles: Cites Crack as Cause

Crack. As in a crack in the sensor mat located in the passenger seat, not the smokable variety. The recalled BMWs include the 2004 to 2005 5-Series standard and sport seat models, the 2004 to 2006 X3 and the 2006 3-Series with sport seats. Apparently, the act of getting in and out of the vehicle can cause the weight sensing mat to degrade, potentially forming cracks that could effectively reduce your body type to "child status" (my phrase, not that of NHTSA or BMW) and deactivate the airbag deployment. Only the curtain airbag would still deploy.

source: BMW Recalls 200,000 Vehicles for Airbag Failures