Motorbike Mount?

[AndyCr15]

I recently bought myself a motorbike. I use my M5000 for satnav using TomTom v6. At present I put it in the clear part of a small tank bag, which works reasonably well, but is rather low to be seen easily.

Does anyone know, or have any cool ideas of how I can mount it on the bike, perhaps on the handlebars? Of course it would need to be waterproof...