EDIT: Leon771 and Logansteno were the first two to guess correctly! The answer is the Vauxhall/Opel Insignia.
I am sold under two different brands in Europe.
I am also sold as a Buick in the US.
I am built in Germany.
I was originally designed to be sold as the Chevrolet Vectra in Chile.
I am available with four wheel drive.
What am I?