Seen it years ago in Lacanau france (custom build).
But is is basically a 5 panel mirror (google it). 160 degrees, no distortion and flat no convex so larger image.
The standard ones are not high enough (tested one). So the plan is to build one 34"x 7-8".
Will update as soon as I got it working ......should get an excellent view of a course run including the buoys (all convex mirrors .... not wide enough and if wide enough... small image of the skier).
Why: ..... if you give instructions and drive... perfect (we ski a lot without a third person).