A tail light for mounting on a motor vehicle having a rear end and a rear bumper extending generally transversely across the rear end. The tail light is mounted to the rear end above the bumper and has a translucent body comprising an upper portion substantially conforming to a shape of the vehicle body adjacent the light unit, a rear portion angled downward relative to the upper portion, and an air separation edge extending along at least a portion of an intersection between the upper portion and the rear portion along at least the transverse direction of the vehicle. The air separation edge delays air flow separation from the rear of the vehicle body, thereby improving aerodynamic efficiency. The body is made of an elastic material to resist impact damage, and therefore may be mounted closer to a rearmost surface of the bumper without being damaged in a collision.