i have to say im on the side of boston right now. that c pillar is now being used on the facelifted trib-y, very likely because saab had already prepared to use it.
furthermore that mock ups rear end give it away. aside form teh rear lamps which are similar to the trib's the general glass area of the hatch is almost if not identical to the trib's
furhtermore from what can be seen of the front doors it appears there is room for the small windows posted between the main A-pillar and the sub a-pillar just as there is on the trib, soemthing that yes the antara concept posseses, but the production one does not, and by looking at the pictures of that saab it is only concept in nature, obviously a mock up of a production version not of a concept show car