At first I was against these being installed as standard on cars in the future. But having seen a few videos recently, I am coming around to the idea. I don't like the idea of them being fitted to new cars as standard, because I don't trust that they won't be used to collect data and transmit it out somewhere. However, if it helps bring insurance premiums down, and helps in some small ways to improve road conditions, then I am all for it.
TopGearRules - I would have been tempted to send the video of the idiot coming out and cutting over the roundabout early on to the Police. There were a few times though I think you should maybe have been anticipating certain events, like the cyclist and the lorry. Had there been an accident, I believe they would have been at fault in both cases, but even so they were both closer calls than they needed to be.
Dash cams are great, but it does mean you need to be nigh on perfect when driving if you want to submit them in evidence in court.