Jarse replied:

Gidday Nick,

I'm not sure whether the 100 series uses a rubber or urethane installation. If it's urethane, you should get it removed/replaced, as these type of installation are actually part of the structural integrity of the roof. There is an inherent risk that the glass can be broken during the process, but if the installer is worth his salt, he should be able to minimise the risk.

If it's only a small area of leakage, you might be able to temporarily stop it with a neutral cure silastic (Never use acid-cure). However, this can expose you to the risk of rust if you don't do it correctly (if you obstruct the drainage path of the windscreen aperture, allowing water to stand in the bottom channel). And remember that once the glass starts to come away from the urethane it will eventually completely separate over time.

If it's a rubber installation, you possibly need a new rubber. Most rubber installations since the early 80's are "self-draining" in the sense that they use very little, or no sealant at all. The problem with these is that over time the rubber shrinks/becomes hard, and loses the ability to seal effectively. You can have a go at stopping the leak with a proprietary windscreen sealant (not silastic), but once again, you need to be careful not to create a situation where the water becomes trapped in the bottom of the aperture.

Hope this helps.