Yup, the Fly6 seems to have many satisfied users for rear-facing cameras. I know of a guy locally whose Fly6 somehow popped off and was already crushed by a car by the time he returned to find it. But he's getting another because he was satisfied with it.

My notion of an ideal commuter/safety documentation video camera would include:

• On-the-fly ability to set markers for important or interesting video segments. Just a button that can easily be pressed to indicate "Mark this segment for review".
• Programmable options to set margins for those marked segments -- let's say, preserve 60 seconds on either side of the marker, even if the rest of the media card is erased or overwritten.
• The ability to auto-erase/reformat a card as it fills. If we record nothing interesting on the ride, why bother even reviewing it? My rides aren't interesting enough even for me to look at, let alone upload to YouTube.

These features may already exist in some higher priced cameras. But not in my budget range.