pillar 5 below the right lower bracket 19 one wheel 27 being positioned to the outside 20 of the longitudinal axis of the right runner track 15 and the other wheel 28 being positioned to the inside 21 of the longitudinal axis of the right runner track 15 vertically above the lower right outside roller wheel 27 a left runner assembly 30 and a right runner assembly 31 rollably engage the wire rods 16 on the left and right runner tracks 14 and 15 respectively each runner assembly 30 and 31 has two roller wheels 29 contained therein which laterally engage the outside 20 of each wire rod 16 the roller wheels 24 25 26 27 28 and 29 are either in or are generally parallel along the radial axis to the plane of the windshield assembly 1 a first driving cable 35 is attached to pount a on the upper section of the left runner assembly 30 the first said cable 35 is brought up along the inside 21 of the wire rod 16 of the left runner track 14 to the left inside upper roller wheel 24 the cable 35 engages the outsides of the inside and outside upper roller wheels 24 and is brought down along the outside 20 of the wire rod 16 past the left runner assembly 39 s two roller wheels 29 the cable 35 then rotatably engages the outside of the lower left outside roller wheel 25 extending through point x to the.