Does anyone know where I can order one with fittings. I 've just removed my dash and the plastic clip collapsed in my hand.

In holland we have this site: http://dafhobby.nl/pages/volvo_360pag.html

I think you need the 'Kilometertellerkabel VDO', if you have mk3

LHD and RHD are different though

There are a few places that make custom speedo cables (Speedy Cables, Swansea come to mind).