Yep, Opel/Vauxhall naming strategy is great fun, as they've slowly come to agree on what things should be called - but never both moving to a new name at the same time...
Thank goodness they've taken that decision LOL
My rides: 2004 Opel/Bertone TS Astra turbo convertible - 2012 Mercedes Benz C204 C Class coupe
Others: 2009 Honda City VTiL sedan - 2015 Fiat 500
Cavalier is Vauxhall's name - Opel went straight from the Ascona to the Vectra. Vauxhall hung onto the Cavalier name for one more generation before switching to Vectra in line with Opel.
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Chevrolet also called its version the Cavalier until discontinued in 2005