WARNING: This page is about a different car, the 2006 Chrysler PT Cruiser. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Identifying Vacuum Reservoir
Courtesy of DAIMLERCHRYSLER CORP.
1 - VACUUM RESERVOIR
The vacuum reservoir (1) is located in the right front fender well on the frame rail. It is made of plastic.