Where are the spark plugs located at on a 1999 Chrysler LHS?

The spark plugs on a 1999 Chrysler LHS (assuming the 3.5L V6 engine) are located on the top of the engine, beneath the plastic engine cover. You'll need to remove the cover to access them. They're arranged in a V-formation following the cylinder layout of the engine.

To be precise, you'll need to look at the engine from the front of the car (grille side). The spark plugs are toward the back of the engine, between the intake manifold and the valve covers.

Important Note: Accessing them may require some maneuvering and possibly removing other components depending on your comfort level and toolset. A repair manual specific to your 1999 Chrysler LHS is highly recommended for precise location and removal instructions, as well as the proper torque specification for tightening the plugs back in. Improper installation can damage the engine.