The Lancia was my expected answer.
But I don't agree that the NG900 to be a rebadge of the Vectra. I would say they are differentiated enough to be separate models. It's like calling a G6 a Malibu Maxx. Platform-mates, but not rebadge.
Also, marketing a car is not rebadging. Opel was marketed by Buick for a while, but an Opel is not a Buick.