Just stumbled across a Utube video on a mirror to allow you to use your rear view tailgate camera with your tailgate down. Www.tailgatemirrow.com. Useful product.
Hang my tailgate at garage ceiling 3 years ago. It is still there. Now the mirror might be useful for some drivers, but who drives down the street on reverse with tailgate down? The suction cups don't work too well od muddy tailgate anyway. Put magnets instead and with aluminium tailgate you are screw again.