Haha the sound is as it is in that video..
If you didn't notice, I had the radio turned up at the start, then turned the volume down and just had the window open..and then booted it at one stage near the end and you can hear that silly holden V6 crying..
its not too bad, a little tinny but otherwise will manage
As opposed to the GoPro Hero cams which don't seem to record decent sound at all..