WARNING: This page is about a different car, the 2008 Buick LaCrosse and 2008 Buick Allure. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Placing Jack Under Center Of Rear Suspension
Courtesy of GENERAL MOTORS CORP.
Lift the rear of the vehicle by placing the floor jack lift pad at the center of the rear suspension.