So I've started to experience a knocking noise coming from what sounds like the trunk (passenger side). It's random and even happens while stopped at a stop light. I intentionally swerve and slam the brakes to rock the car and the knocking is not related. I've searched this forum and all I can find is suspension related issues. What throws me off is that it happens sometimes up to 15 seconds after stopping. Could this be suspension or maybe gas sloshing within the tank? Happens even when the tank if full.