Head-up Displays (HUDs) are not exactly a cutting-edge technology any more. However, they still demand a great deal of space. A new HUD based on holographic projection could be squeezed into a space as small as a car’s side mirror.
Just imagine being able to see additional data, graphics or other warnings overlaid on what’s actually in your side mirror or perhaps your rearview mirror. What may be better or at least additional is a HUD display on the windscreen itself.