Ok so after some twerp decided to cover my windscreen and bonnet with tomato sauce while I was at work. I am now looking at dash cams,
I have found this one on ebay
http://www.ebay.co.uk/itm/251749193955?_...EBIDX%3AIT.
With it having the function to constantly record and has a battery drain prevention device I just wondered if I would be able to wire it into the lights in the roof instead of running down the a pillar/door.