This is most likely to be your parcel shelf rattling around. A guy from Vauxhall gave me a tip that if you fill the two hollow rubber tubes that are attached to the tailgate which push against the parcel shelf with tissue it will stop the noise. I did this and sure enough the squeaking stopped.
The shelf in a hatch back is a partial shelf. A parcel is a package.
it is the front parcel shelf which hangs down in a delivery vehicle. used for holding parcels.
Package tray or parcel shelf.
Dynamat
Inside the fuel tank. To reach the fuel pump, you will need to go underneath the parcel shelf behind the seats. # Move the seats forward. # Remove the plastic clips that keep the interior carpet down that covers the parcel shelf (runs behind the seats, parcel shelf is what the soft top rests on when it is down). # Pull back the carpet, you'll see a metal pan that provides protection of the tank and shape to the parcel shelf. # Remove the shelf by removing the several bolts around the metal pan. Be careful, it's sharp!
4.5"
is it a hatchback or estate?
balance it
* Remove the rear seatback * Remove one of the rear quarter trim panels * Release the four plastic push-in retainers that secure the rear parcel shelf disengage the rear seat belts from the slots in the parcel shelf and remove the parcel shelf * To disengage either rear speaker push down on the tab on the front of the speaker spacer lift the speaker and pull the speaker forward.Unplug the electrical connector and remove the speaker from the car
The heat shield on top of the converter may have broken loose. it can be repaired. If the rattling is inside the converter it must be replaced.
The best way to stop the rear brakes on a Mazda 626 from rattling would be to replace them. New brakes can cost between $20 and upwards of $100 depending on the quality of the brakes.