A library of Solid Back-painted Glass-like materials is available for licensed users.
You can see an example rendered with this material library here (NOTE: It's only used on the top surface, not the side panels which show a double reflection a different way, see the original thread for full information.):
Originally this image was shown in this post:
Subject: light and material study
The library for licensed users is available here:
Subject: Perfect Reflection Library Like Glossy Solid Acrylic