1.  Field of the Invention
The present invention generally relates to a vehicle body structure that includes a window covering assembly.  More specifically, the present invention relates to vehicle body structure that defines a window opening and a window covering assembly that completely covers window glass in the window opening in response to an impact event. 
2.  Background Information
The National Highway Traffic Safety Administration has published new rules related to impact events and vehicle ejection mitigation.  Specifically, Federal Motor Vehicle Safety Standard (FMVSS) 226 Ejection Mitigation sets forth compliance criterion for countermeasures that must reduce occurrences of complete and/or partial ejections of vehicle occupants during impact events, including rollover events.