I'm surprised Opel/Vauxhall aren't a launch partner as I think the Opel/Vauxhall Adam was the first European car to have Siri Eyes Free. Also the Keynote slide Eddy Cue used to announce iOS in the Car showed the Opel/Vauxhall (I think Chevrolet in the US) Intellilink infotainment system working with iOS in the Car.
Hopefully more models will be announced at Geneva
Opel/Vauxhall is "GM", not Chevrolet (which is also GM, so you're not totally off).