Michael,
I like your idea, in fact I kinda thought about something similar. But, I thought that the light would shake a fair amount mounted like that. Have you found that the vibration affect the light enough to bother you?
I had also thought about putting something like how the wheels are mounted on the MMM. A shaft with holes drilled in it and you could put a pin through it. This would still let me mount the light on the underneath the top of the roll bar (hanging down) while still being able to aim forward or back. Plus, whatever I use to mount it on the roll bar I could use a rubber piece to help reduce vibrations.
GlueGuy,
If you come up with something, plase let me know. I will do the same if I see something. I found a set of lights I could pass up for the price, now I need to find a method of mounting that I like.
/James