Pontiac was an automobile brand that was established in 1926 as a companion make for General Motors' Oakland. Quickly overtaking its parent in popularity, it supplanted the Oakland brand entirely by 1933. On April 27, 2009, amid ongoing financial problems and restructuring efforts, GM announced it would discontinue the Pontiac brand by the end of 2010 and focus on four core brands in North America: Chevrolet, Cadillac, Buick, and GMC. The last Pontiacs were built in late 2009, with the final dealer franchises expiring October 31, 2010. For an extended period of time—prewar through the early 1950s—the Pontiac was a quiet, solid car, but not especially powerful. It came with a flathead (side-valve) straight eight. The Bonneville, a sub-series of the Star Chief introduced with the 1957 models, then, became its own line. Due to the popularity of the GTO option, it was split from being an option on the Tempest LeMans series to become the separate GTO series. On the technology front, 1966 saw the introduction of a completely new overhead camshaft 6-cylinder engine in the Tempest, and in an industry first, plastic grilles were used on several models. The 1967 model year saw the introduction for the Pontiac Firebird pony car. In mid-1971 Pontiac introduced the compact, budget-priced Ventura II. 1971-1976 model full-szie station wagons featured a 'Clamshell' design where the rear power-operated glass slid up into the roof as the tailgate (manually or with power assist), dropped below the load floor. The power tailgate, the first in station wagon history, ultimately supplanted the manual tailgate. For 1973, Pontiac restyled its personal-luxury Grand Prix, mid-sized LeMans and compact Ventura models and introduced the all-new Grand Am as part of the LeMans line. For 1975, Pontiac introduced the new sub-compact Astre. In 1976, the Sunbird. Introduced in 1982, the wedge shaped Firebird was the first major redesign of the venerable pony car since 1970. Partly due to the hugely successful NBC television series Knight Rider, Next came the 1984 Fiero. The last American Pontiac, a 2010 G6, was built on November 25, 2009, at the Orion Assembly plant.