A motor vehicle body including a plurality of vertical pillars defining therebetween a plurality of door frames for access to a passenger compartment of the vehicle body, a plurality of doors supported by pairs of hinges on the front vertical pillar of each door frame for pivotal movement between closed and open positions, and a light weight side impact protection barrier characterized by high elongational stiffness and high strain-at-failure. The light weight barrier may be employed alone or in combination with a horizontal door beam and includes a synthetic cable in the door made from a plurality of helically braided bundles of fibers selected from a group of fibers consisting of aramid fibers and liquid crystal polymer fibers characterized by a strain-at-failure exceeding about 3%. The synthetic cable includes attachments to the front and rear pillars of the door frame when the door is closed. The synthetic cable is very stiff in tension to suppress intrusion into the passenger compartment and has a failure mode characterized by serial or sequential failure of individual ones of the fibers rather than simultaneous failure of all of the fibers.