Lee, I had a look using a torch with the tyre on as its a bit dark to take them off, it just seems to be the plastic arch against the tyre wall, i can't feel any wear on the metal plus its covered it dirt so hopefully that means the tyre isn't rubbing there. The rest of the tread is fine, no uneven wearing or anything. I've pulled off some of the plastic that has worn away but its how far down the tyre wall that has been worn concerns me the most incase i have to get my arches reshaped. But the unusual thing is the front tyres are totally fine, no rubbing or wearing even on full lock.
Update: Just been out for a quick drive and its a 90% D/S Rear problem, more wearing and more noise there than from the P/S Rear, also got 2 mates to sit in the back while I had a look and I think about half an inch of arch will have to be cut, as the tyre wall sits pretty much flush with the inside of the plastic trim. Will try and post a pic tomorrow if it would be any help.