Building Up The Effect

After a failed attempt to get the scene rendering in vRay (its being funny about rendering nParticles), I rebuilt the scene from scratch in Maya 2014 (it was in 2015 previously). I also went out and shot an IBL to illuminate the scene and provide the rain something to refract.
I managed to create the "streaking" effect by using instanced geometry over the particle system, I had previously tried to create the effect using motion blue, but the result was not as good and it increased the render times too much.
Currently the scene is also using Maya's simple fog environment shader to provide a bit of atmospheric perspective.
I have here a play-blast of the effect as it is currently, as well as the IBL I used.