I get this loud knocking sound when i over bumps or cracks in the trunk. I am not sure if its coming from underneath or in the trunk. I checked the trunk nothing is loose. I took it to mechanic he said there is a play in the trunk arm i am not sure if that will fix it. ANything else that can make sound loud knocking sound also it doesn't happen all the time. also the ride is little bumpy any suggestions or anyone else experince this