Same idea myself. After ordering two different style cameras and a monitor from eBay so waiting on them to arrive before I can give any help. Regarding the two cameras, both have ir but one is a surface mount and the other is a flush fit similar to the old hall door style peephole. I was thinking of fitting the camera originally to the inside of the high mount tail light on the boot door but as the rear glass has mid black tint on it I'm not sure if that will affect the ir sensor. Hence getting the other camera as reserve. Anyway, if I get the stuff in the post soon I'll post up a few photos. If you start before me, keep us updated.
Tony