I finally managed to get round to replacing my mirror glasses (having not been able to see behind me for a week) The wiring was indeed already there and it was a simple case of plugging in the new heated glasses. They work in conjunction with the HRW. Result! Cost nearly Ł80 from the stealer but glad I did it. Still can't get my head round why they don't come as standard on a Ł33K S-line. Thanks to all those that posted info on the subject