Hacker develops rear window LED to send messages to other drivers
• Digital TrendsWith aggressive drivers that enjoy tailgating other vehicles in mind, a hacker decided to built a method to communicate to those annoying drivers without using obscene hand gestures.
I had this idea years ago, but was going to use the red LED bar-type display because of Arizona Law:
28-931. Lamp colors
A. Front clearance lamps and those marker lamps and reflectors mounted on the front or on the side near the front of a vehicle shall display or reflect an amber color.
B. Rear clearance lamps and those marker lamps and reflectors mounted on the rear or on the sides near the rear of a vehicle shall display or reflect a red color.
C. All lighting devices and reflectors mounted on the rear of any vehicle shall display or reflect a red color, except that:
1. The stoplight or other signal device may be red, amber or yellow, except on a commercial vehicle, as defined in section 28-2231, the stoplight shall be red and the other signal devices shall be red or amber.
2. The light illuminating the license plate or the light emitted by a backup lamp shall be white.
http://www.azleg.state.az.us/FormatDocument.asp?inDoc=/ars/28/00931.htm&Title=28&DocType=ARS
Otherwise, you'd get pulled over in a heartbeat with 'white lights in the rear' other than license plate or backup light.
That, and you'd better use 'pre-configured' displays or get an additional ticket for 'distracted driving'.