What exactly is creaking? Is it the sway bar (sounds more like squeaking than creaking)? Under what conditions does it happen?

My experience with "creaking" is that the chassis tends to creak when traversing a driveway diagonally. The rear of these cars is weak until/unless you install a strut tower bar. The trunk pass through is a notoriously "weak link" in the chassis.

Need more info. and observations to correctly diagnose your problem.

Redcoat Raceworks. Performance parts and custom fabricating for Contours, Mystiques and Cougars. Specializing in chassis and suspension parts. Custom end links, control arms, strut tower bars, engine torque braces, etc.