azander

I think the mounting frame for the light housing is adhered to the glass (with double-sided tape), and the black etching on the glass hides this (wouldn't look very good without the etching).

GeorgeK

I have a 993 thin, defrost-less rear glass on my '89. Added advantage is that the 993 glass is a *tiny* bit larger (1-2mmin each dimension), which provides a very positive gasket contact. On my car it has helped resolve the tendency the gasket had to "fall in" in the corners.

Bruni

I have one in my 964.