Well, I couldnt find any better system that would meet my needs of low power consumption and automatic loop recording. So I just pulled the trigger and bought the sd dvr:
and a cctv camera (I hope those are real ir leds):
Also bought some lm317 voltage regulators so that I can hook them up in the car. Total cost is just a little over $100CAD. The whole system should draw under 5 watts and will be run from my auxiliary deep cycle battery. Although having a high frame rate would be great, I think I will just set the system to automatically take pictures when there is motion. Hope this works.