Alphamoose

Minoura has a light mount that replaces one of the spacers on your stem. Seems to put the light in a useful position.

Murray Missile 

Thanks for bringing that up because it had totally escaped me. You make a valid point that fortunately has a simple solution, seal the entry hole with RTV. I had a fog light on my old Suzuki mounted upside down on the case guard, since I often rode in the rain I sealed the wire harness entry hole with RTV. I'm going to do it to my bike headlight even though it is mounted right side up. We don't get rain like the Pacific NW but we get some pretty powerful thunderstorms, sometimes they're real frog stranglers with very high winds and water gets in everywhere. If you get caught in one of those, which I have, water could still follow the cable or run down the sides of the housing and creep through the grommet due to capillary action. It probably wouldn't be enough to short out the light but continual exposure to that little bit of moisture over time would cause corrosion.