"A head-up display or heads-up display—also known as a HUD—is any transparent display that presents data without requiring users to look away from their usual v

"A head-up display or heads-up display—also known as a HUD—is any transparent display that presents data without requiring users to look away from their usual viewpoints." With glass you have to look UP and the screen is almost never on. http://en.wikipedia.org/wiki/Head-up_display http://en.wikipedia.org/wiki/Head-up_display