Muzz- you could try another way to prevent theft, by fitting a Diskloc on the steering wheel, heard good reports on them, and they are still a good visible deterrant.
Hi Muzz, a good security tip for m/homes if your drivers seat is on slides is to move it forwards as far as it will go towards the steering wheel then drill a 10mm hole thruogh the lower track just behind the uper track and fit a long reach padlock. this is a very good deterant. it has worked on my van for ten years,