Legal Disclaimer: This is a proof of concept only and is not nor is intended to become a real product. If you live in the United States, most likely a rear window LED display is not legal in your State.
Smart Brake Light Prototype using the PIXEL LED Art Display and OpenXC. More info on PIXEL at http://ledpixelart.com/portfolio-item/smart-brake-light-prototype-2/ including source code and OpenXC at http://openxcplatform.com