You need to be a bit careful here, it all depends on which model you have, whether you hav the cable in place!!
I made precisely this mistake.. I have a 2.5TD estate, 1996 and it is the GLS model. Was told exactly what you are being told. Bought a CCR600/CDC2 setup, and when I got to fit the CDC2... no cable in the rear end. Was told I needed the cable from the Drivers footwell to the rear end, plug 'n' play, they said.
BUT. having splashed out on a s/h cable from a breaker £20!!, (they are £40+ new FFS!) found that the required connector in the drivers footwell didn't exist in the GLS model!!
Ended up buying an'aftermarket' cable which goes between the HU and its loom, and through to the rear right hand boot pocket.
Apparently the 'poorer' models had no loom, but the 'top end' models have it all there ready to hook up.
Be interesting to know which model you have. Also, take off the drivers footwell panel, (where bonnet release is) and see if there is a large unused multiway connector mounted on top of a black ECU box.
If there is, then wiring is in place. (I have a loom that you can have (see above!!) If not, then its down the same route as I had to go.
Actually, quite a reasonably easy one..
Just hope this helps!! especially if it saves you buying the wrong loom!!!
