Give the car a look over again today and removed the BMW badge from the side of the M badge on the back and removed the M badge from the front grille. Put the back of the car on the ramps and found the diff bush quite worn so it will need replacing. Think its running the M-Sport suspension, may be springs that make it low. Also noticed a sticker on the chassis under the bonnet that says its a an Individual. Going to remove the glass over the two round lenses within the front lights to give the lights a better look as my mate has done this with his previous M3's and M5 and it looked better.
Did a bit of research and the bush is a rear beam bush, maybe that is causing the play/wheel movement as its proper worn, think the bottom of the bush is completely worn away. The sensor may be a brake sensor and not an abs sensor as there are no warnings on the dash.