Hi there, we are having a tough discussion among friends concerning this topic: Imagine you are inside your car, stopped in the road. There is no obstacles in front of you, just plain road. Suddenly, because of the sound coming from the back, you realize another vehicle is going to impact you at the rear. Would you break or not? Why? I decide not to brake to release part of the energy of the impact thanks to the more "rolling-free" movement of my car. This will also lead to get less damage/deformation in both cars. Thanks to all answers, cheers!