Carradice saddlepack and lights

[skut]

I'm thinking of getting one of the Carradice Super C saddlepacks for long distance rides, but was wondering whether they interfered with the fitting/visibilty of rear lights? Will there be enough seatpost left below the pack to fit a decent light?

Thanks

 

[yello]

I would imagine that visibility would be impaired. Can you mount the lights on the saddlepack, or even the outside seat stay?