Opel cars appeared under their own name in the US from 1958 to 1975, when they were sold through Buick dealers as captive imports. The best-selling Opel models in the US were the 1964 to 1972 Opel Kadett, the 1971 to 1975 Opel Manta, and the now-classic 1968 to 1973 Opel GT.[54][55] (The name "Opel" was also applied from 1976 to 1980 to vehicles manufactured by Isuzu (similar to the "Isuzu I-mark"), but mechanically those were entirely different cars).

The GSi's engine mapping had been carried out by Opel tuning specialists Irmscher. A model with the 82 PS (60 kW) 1.4 L multi point fuel injected engine, which was otherwise mechanically identical to the GSi, also became available as the Nova SRi in the United Kingdom. In January 1988, a turbocharged version of the Isuzu diesel engine was introduced, with power increased to 67 PS (49 kW).[8]