WARNING: This page is about a different car, the 2002 Chevrolet Malibu. However, it is still accessible from the selected car via links, so may be relevant.
Position the floor jack pad as follows:
Fig 1: Jacking Under the Rear Suspension Crossmember
Courtesy of GENERAL MOTORS CORP.
Important:
The floor jack pad must not be placed under the (rear suspension crossmember) front reinforcement rib.