I noticed that the bottom of one of the rear seat belts for the 3rd seat felt cool; that could mean but one thing, they were getting wet. I found water collected in the area where the rear shock mount was located, see photo.

The water had to be coming from the side window in the loading space. I took out the window and yes, there was some rust, see other photo. One the other window there was also rust in the other corner on the bottom. The rust is not visible with the window installed from the outside, although if you look real carefully from the inside you may be able to see some if you lift up the rubbler gasket from the lower corners.

The the stuff that was used to install the window by MB was the consistency of of dried out putty.

I've fixed one window so far. Used POR 15 on rust. Used 3M 08509, it's a bedding and glazing compound to seal gasket to vehicle body and glass to gasket.

Attached Thumbnails