Hi guys,
Just a quick note to say that I managed to pull this one out. What a hassle!
Basically the cable ran from the dashboard, under the armrest, through a little slit in the carpet, under the passenger's back seat (still under the carpet), up the side, behind the rear right panel and then through a small hole...into the trunk!
I managed to 'lift' the carpet a little, enough to give me the confidence that I wouldn't have to rip out all the upholstery to remove the cable. I then removed the rear panel and from there on it was a simple case of pulling the cable slowly until it was all out.
cheers,
milton