On a 1999 Chevrolet Malibu with a V6 engine, the fuel filter is typically located
on the frame rail, near the fuel tank, on the driver's side of the vehicle. However, it's not always easily accessible and might be partially hidden. You'll likely need to get down low and possibly use a flashlight to locate it.
Because its exact placement can vary slightly depending on the specific trim level and options, a visual inspection under the vehicle is recommended. Referencing a repair manual specific to your 1999 Chevrolet Malibu V6 will give the most accurate location and detailed instructions for replacement.