WARNING: This page is about a different car, the 2007 Pontiac G5 Pursuit, 2007 Pontiac G5, and 2007 Chevrolet Cobalt. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Hood Insulator Push-In Retainers
Courtesy of GENERAL MOTORS CORP.
Position the hood insulator (2) under the tabs that are located at the front and center of the hood.
Install the hood insulator push-in retainers (1) until fully seated.