The new-for-2011 Saab 9-5 can be called the spiritual successor of the 9000, as the original 9-5 replaced the 900's big brother more than a decade ago. This new one, however, isn't totally unique. Even though GM sold Saab to Spyker in 2010, the new 9-5 is still built on GM's Global Epsilon II platform—just like the Buick LaCrosse and …