Re: How is your rear plate installed?
Mine only had two plastic pieces, a 12. Mine had the cheesy dealer plate, so I took it off and got my college alumni plate. Thankfully, they had a nice looking won out of the few they had. I prefer plates with frames, idkw, I just do.
But back to you, if you think the screw will go through to the metal, I would definitely get a frame.
When life gives you lemons, run that crap over.