Side reference line (SL) definition
Side reference line (SL) means the geometric trace of the highest points of contact between a straight edge 700 mm long and the sides of the front structure, A-pillars or roof, when the straight edge, held parallel to the transverse vertical plane of the vehicle and inclined inwards by 45° and with the lower end 600 mm above the ground, is traversed down the sides of the front structure, A-pillars or roof, while maintaining contact with the surface of the body shell (see Figure 8).