[carmine]

The rod in the middle of the windscreen is there to prevent the top from pulling on the windshield upper frame thus separating it from the glass
this happens at above 60 mph when the outside air pressure is higher than the inside cabin pressure or when side curtains are left off and air rushes in and creates exsesive kite like pressure on the top.
If this is allowed to happen without the center support rod in place the upper windshield frame pulls up off glass and creates a bowed pressure stress on the glass and eventually will crack the glass.