* loose cargo: The most common cause is simply loose cargo or other objects that are moving around in the trunk. This can create a rattling or banging noise. To fix this, simply remove the loose items or secure them so that they cannot move around.
* Spare tire: Another possibility is that the spare tire is not properly secured. If the spare tire is loose, it can move around and create a banging or rattling noise. To fix this, simply tighten the spare tire down so that it is held securely in place.
* Suspension: In some cases, a noise from the trunk can also be caused by a problem with the car's suspension. This is more likely to be the case if the noise is a knocking or clunking sound. To fix this, you will need to have your car inspected by a qualified mechanic.
