What's the best dash cam with a parking mode?

My car keeps getting scratches, scuffs and even dents from dishonest drivers who I suspect damage my vehicle whilst it is stationary and unattended and then drive off. Can you recommend a camera that could...

Why don't manufacturers offer factory fitted dash cams?

While reversing cameras are now common on cars I am not aware of any manufacturer offering a factory fitted dash cam even at extra cost? Such a feature could easily be incorporated in the interior mirror...