rear suspension noise

Hi, my name is Devin. I am an auto repair expert with the Car Genius team here at RepairPal. I'm sorry to hear you're having trouble with your MKZ. Even though you've replaced the rear shocks and sway bar bushings, the noise could still come from worn-out sway bar links, control arm bushings, trailing arm bushings, or many other components. These components wear over time and can cause rattling or clunking noises when driving over rough surfaces. It's also worth checking the rear suspension springs for cracks or wear. Since you've done most of the basics, having a mechanic perform a detailed inspection to pinpoint the source might be a good idea. If you need more advice, have any other questions about your vehicle, or would like to get connected to a RepairPal Certified shop near you, we have you covered. Give us a call at 877-913-1554, and we will happily help you out!