Chevrolet's 1968 material shows Astro Ventilation and front-door glass without the 1967-style vent panes. The exterior also carries front and rear side-marker lamps, making the marker lamps plus one-piece door glass the most useful quick visual distinction from a 1967 car.
The factory order material establishes the Z/28 as a regular orderable special-performance package for 1968 rather than a one-year 1967 experiment.