Side airbag deployed for no reason while driving straight at the speed limit of 75 mph. The local VW dealer determined the side impact sensor is defective. This is a very interesting situation because a fail safe exists in these systems in that the supplemental restraint control module in the center of the car must simultaneously "see" a side impact g force in order to deploy the side air bag. In other words even with a defective side impact sensor The side air bag should not have deployed. At the time of the incident the vehicle was travelling straight ahead next to a semi truck. No such impact occurred and the VW dealer confirmed the vehicle has no evidence of such an impact. I had this investigated by Volkswagen AG and my local dealer. Suffered broken teeth, bruised ribs, hearing loss in left ear.