I agree with you, Edouard.....a GS wagon with a 6 speed manual for the mid $30s could be the car that gets me into a Buick showroom.
As far as the relationship between Opel and GM, yes GM sold them to Peugeot/Citroen. However, from what I've been reading, the relationship to sell re-badged Opels in the US as Buicks remains. But, likely will be the last......the next versions will probably end up coming from China, unfortunately.