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?