A significant amount of water is collecting at the base of the Xenon headlight lens. No outside influence, such as rock chips, can be found. The headlights function normally. If the customer complaint is only about condensation buildup on the fog lamp (not about water collecting as described above), refer to TSB 2012749, 94 Exterior lights, moisture accumulation. Under certain circumstances, water can enter through the headlight adjustment screw (A4), or through the bonding channel between the headlight housing and lens (A5).