Very cheesy way to do it. I know the prices are a lot lower on the Vee-Dubs, but on all of my BMWs and Porsches there has always been a black, ABS style plastic mount that is secured to the rear bumper for mounting the plate and/or a nice frame to.
I usually use the black frame and glass lens Prestige brand license plate frames, but they are way too heavy to be held simply by screwing them in to the bumper.
I gotta do a web search and find a better solution..........