This is pretty smart idea.
Using principals of Optical Camouflage, researchers at Keio University project the image from a camera on the back of a car onto a recursive reflector which looks like one of those glass screens politicians use for their teleprompters. The mirror sits at an angle to project an image right where the backseat would be,essentially making the back seat disappear.
As you can see in the video, it’s really useful when backing up your car to see all the objects behind you in context and in the proper size, lined up with everything else you see out of the rear view mirror.
– via DigInfo TV