rear side window spots?

[2Gunz]

The read side half windows (or whatever you would like to call them) have what looks like water spots on them. They refuse to come of the window.

I tried cleaning the windows with everything I can think of. Yet it still wont come off.

This is a factory air car with the orginal windows (or at least they seem like it).  This some sort of factory defect?

I want the "water spots" off any ideas?