Under the Engine Front Crossmember Frame
WARNING: This page is about a different car, the 2008 Cadillac CTS. However, it is still accessible from the selected car via links, so may be relevant.
Courtesy of GENERAL MOTORS CORP.
IMPORTANT:
The floor jack pad must not contact the oil pan, splash shield or the steering linkage.
Position the floor jack pad under the center of the engine front crossmember frame.