[beautimus]

a trick i have used for a temporay fix, is to use electrical tape.
the vinyl electrical tape can be curved like pin stripe tape so it makes it easy to folow the curvature of the front edge of the glass. it will take several tries to get it right, but you can overlap the chrome edge on the glass onto the rubber surround, on the front edge, top, and bottom of the glass. do this inside and out. If you hold the glass in place all the way around while you tape it, the rear edge should take care of itself. the thing i like about the electrical tape fix is that it doesn't call attention to itself. so thieves don't realize that the vent window is compromised. eventually you need to fix it right because the vent windows are pretty vulnerable to break-ins as it is.
goof luck,
tony