EC Mirror Cell
WARNING: This page is about a different car, the 2002 Lexus ES 300. However, it is still accessible from the selected car via links, so may be relevant.
An EC mirror cell consists of 2 layers of glass which sandwich the EC elements in the middle. See Fig 1. The EC elements control coloring and discoloring characteristics through their electro-chemical oxidation reduce reaction. These characteristics are utilized to electronically vary the mirror's reflection rate.