Not sure if this was covered elsewhere, my apologies if it was. I have been wondering if the brake lights come on when using regenerative braking and your foot is not on the brake pedal. The reason is that the regen braking is awesome and slows the car down a lot, which is great for one pedal driving but what about the un-attentive driver behind you who doesnt have situational awareness of the traffic ahead and merely reacts to your brake lights? So I decided to do a test tonight and am happy to say the Tesla Engineers have you covered. The Brake lights will come on when the regen is applied and the car slows down. Once the car is coasting at a constant speed the lights will turn off. If you are using the low Regen setting, the brake lights do not come on immediately but only when the car starts to slow significantly. If you are going down a hill and the car is coasting at a constant speed, again the lights will go out. I continue to love driving this car.