Yeah, I'm looking to do it like that too, hardwire to the ignition like my DRLs, and have it overwrite itself unless it senses a collision. I passed that video to the NZ Police, so I'll see what becomes of that next week. Probably might not get a response though, its only a community report thing, but it should still give him a nice shock to learn that unfortunately for him the person he decided to pull that stupid stunt on had a dash cam rolling.