Mounting a GoPro on my rear bumper

I like recording my road trips and wanted a to put on a rear-facing GoPro to compliment the one on my dashboard. Any ideas on how to secure this on there? I like this little spot for it. It's a cool vantage point.

There is about an inch of space above the GoPro. And the bottom lip of the tailgate actually obscures the lens a tiny bit, but I think it looks cool that way.

 

Could you fab up a bracket and secure to one of the taillight mounting screws?

 

Problem with putting it there is the tailgate will crush it when opened. Maybe get some brackets made for LED lights for the rear and mount it there? also could do a suction cup mount and stick that sucker on the roof

 

Or the tailgate. Or get a CB antenna bracket and use a 1/4x20 bolt to mount it to a gopro tripod mount.