Thanks for the reply Booth11, I didn't get a rear camera. The whole thing was a sort of impulse purchase when I realised the garage were taking off the pillar trim to try and cure my rattle. Thought I might as well get hard wired camera fitted at the same time by the garage to save the possibility of another rattle appearing if I had that done by someone else later.
I've taken it out tonight but I do feel I probably won't bother in future as I already have to fuss a little more due to the extra security measures I use now, don't want another car disappearing into the night....but then also don't want someone smashing the window to nick dashcam....dilemma.