Its likely the leak is coming from the seal around the glass itself not the outer edge of the panel. Unfortunately this is a real problem since at least for me getting a replacement seal was not possible except by having it custom made at a glass shop. I did away with the glass and the headache completely. As others have said, put a hose on it see where the leak starts. Marker lights are another possible culprit. Whatever you do use butyl tape not caulking when you reassemble...Mike