Rear Window Defogger Grid: Description
WARNING: This page is about a different car, the 2003 Jeep Liberty. However, it is still accessible from the selected car via links, so may be relevant.
The heated rear window glass has two electrically conductive vertical bus bars and a series of 11 horizontal grid lines made of a silver-ceramic material, which is baked on and bonded to the inside surface of the glass. The grid lines and bus bars comprise a parallel electrical circuit.