Just thought I'd stick this up. I did have a flexible noodle as suggested by southbound. In theory these should work well, however the one I was sent was different from the advertised item and had a big ugly plastic section where the cable met the noodle part. I no they exist with just the small metal sleeve as i've seen them but do check if you go this route as the plastic sleeve eliminates the flex to much on smaller frames.
This is my final solution- a Problem solvers Travel Agent. It works great and allow very smooth cable movement. The cable guide is also drilled a few mm to take the cable outer.