How does the reflection work?
The reflection of the message from the dashboard onto the windshield is activated by daylight or streetlights shining through the windshield from the outside and onto the card on the dashboard, thus reflecting the letters back onto the inside windshield. The placement and positioning of the cards near or at the area where the dashboard meets the windshield, brings the reflection to the lower portion of the windshield and permits the driver to shift his attention from the reflected words to the view of traffic conditions ahead of the vehicle without a great change in the focus of his eyes.
