The 1966 lineup remained essentially unchanged from 1965. One change of note was a new four-speed synchromesh transmission using the standard Saginaw gear set with 3.11:1 first gear ratio used by other GM 6-cylinder vehicles. The steering column was changed to a two-piece design with universal joint, lessening the danger of intrusion during a front-end collision (actually a mid-1965 running change). A plastic air dam was installed below the front valence panel to conceal the front suspension and underbody, and lessen crosswind sensitivity. In front, The "lock door" emblem (covering the lockset for the trunk lock) was changed from red to blue and featured a shorter bar. At the rear, new larger taillight lenses were used featuring a thin chrome ring around the center of the light. Air conditioned cars received a new condenser that was mounted in front of the engine, eliminating the previous unit mounted atop the engine, requiring its removal for most engine service. The Corvair script nameplate was moved from atop the trunk lid to a position next to the driver's side headlight bezel. Sales began a decline as a result of Ralph Nader's book highlighting the Corvair's deficiencies — and the new Mustang offering V8s up to compared to the Corvair's top powertrain. Rumors of the upcoming "Panther" — the code name for the forthcoming Camaro, slated as a direct competitor for the Mustang — further undercut sales. A decision was made to discontinue further development of the Corvair. Production for the model year was down to 103,743.