The savvy folks on this forum probably already know this, but I couldn't find the answer when I searched. Then, today I stumbled upon the answer in my own car. We know that the rear brake lights come on by deceleration - usually from the regenerative brakes - in addition to the traditional method of coming on when the brake pedal is pressed. I've been curious to see when the lights are actually on. If you go to the "about" screen by pressing the big T at the top, middle of the touch screen, you will get a picture of your car, VIN#, and firmware version/release notes. Pay attention to the brake lights on that picture - now press the brakes... the picture is a real-time version of the car, with active rear brake lights. It works while driving too.. cool for a few minutes, then it's yet another distraction. Nonetheless, it allows you to understand what the guy behind you is seeing as the car slows down.