directly above the defrost vents. I have never encountered this in any other auto I have owned, and wonder if it is common, like MB indicates it is.
Has anyone experienced condensation forming on the exterior of the windshield on 2009 Mercedes-Benz ML320 BLUETEC
maybe your heater core is leaking or vent tube is clogged
good old germans. seek diag as to issue and get est.poss heater core or other coolant leak