Identification :
W164 Series 1 = Bottom of Head Light Is Flat Line when meeting bumper
W164 Series 2 = Bottom of Head Light Drop Down into the bumper near grille area

There are 2 Types of W164 Series 2 Fog Light :
Type 1 (2005~2006) = Round behind Fog Lamp Cover
Type 2 (2006~2007) = Oval Shape