It's otherwise a photoshop (threads on other forums point to this, as they mention a guy posting the pictures on my350z and saying it was a photoshop), or they are display wheels.
It may be possible to make plastic wheels to support the weight of a car, but a wheel has to do so much more than just support weight. Braking forces, accelerating forces, bumps, sideways forces, resist heat from discs etc. I don't think it is currently technically possible to produce a wheel with a plastic centre like that, that could be used for day to day driving.