When driving, and whenever there is a change in road level, I hear a cracking noise coming from the area of the trunk in the back. I removed everything from the trunk, but the noise is still there. I thought it was coming from the tailgate or the rubber seals of the tailgate. I applied grease to the rubber seals and adjusted the rubber stoppers at the bottom of the tailgate so they press firmly against the trunk. But the noise is still the same. It’s driving me crazy. Where is it coming from? The rear suspension, the tailgate, or something else?