I have had one now for a little over two years. It is plugged in to the 12 Volt Power Point on the Dash. I have to actually push in the plug in order to start it.
I have a 32 Gig SD Card and record in 5 Minute Segments. It runs for about 8 Hours before over writing onto itself.
Comes in handy as a Video Camera when You forget yours at Home!
I think Mine was $35 on E-Bay with Free Shipping. The SD Card was almost as much 2 Years ago! It is identical to the First one shown on the Comparison Chart.