Reliable information for an Opel Omega can be found at the official Opel website. They have a comprehensive database regarding all their released models.
It was built by Opel as a version of their Opel Omega, in Rüsselsheim, Germany.
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Timing marks
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The Holden VN Commodore was released on 17 August 1988. This, and subsequent versions based their bodywork on the Opel Senator and Omega. The VN was also similarly based on the Opel Omega.
Opel Insignia was created in 2008.
Opel Antara was created in 2006.
Opel Regent was created in 1928.
Opel Vectra was created in 1988.
Opel Rekord was created in 1953.
Opel Olympia was created in 1935.