Like the Bitter CD, the Bitter SC was based on Opel's biggest contemporary model, this time on the Opel Senator, and was sold from 1979-1989 as a coupe, sedan and convertible. The SC was powered by a fuel-injected Opel 3.0 l-I6 (177 hp) or a stroked 3.9 l-I6 that developed 207 hp (154 kW). Body design seems to have been heavily influenced by Ferrari`s 400i.
The first SC model to appear was the Coupe (1979), followed by the Convertible (1982) and the Sedan (1984). Production lasted until 1989 with 461 Coupes, 22 Convertibles and only 5 Sedans built.
In 1984 it was announced at the New York Auto Show that Bitter would enter into a limited marketing agreement with General Motors in North America to market the sedan in the United States through participating Buick dealerships. A major reason for the venture was GM hoped to take back market share that was being lost to BMW at the time, but concerns were the Opel line was too entry level for the task. Ultimately, less than a dozen Buick dealers, mostly in the metro New York City area, would bear Bitter signage and few Bitter cars were actually sold in the U.S.
The ultimate failure of the Bitter brand was rooted in its business model. As was popular in the late 1970s and 1980s, rebodied vehicles from other manufactures gave rise to smaller automobile companies. The Bitter vehicles were based on components from Opel. This approach became unpopular in the late 1980s and doomed the brand.