is it a hatchback or estate?
If you have a 4-channel stereo installed, then there is a point. The door speakers would be front, left & right channels, the parcel shelf speakers would be rear, left & right.
if u are fitting after market speakers it is important that u dont cut holes in parcel shelf it may attract a defect . generally spacers are fixed to shelf and speakers secured to them
* 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
To remove a 1993 Nissan maxima rear speakers you will have to remove the seat back, you will need a wrench to remove both of the bolts on each side. The seat will move once done, and then pop the parcel shelf trim. The speakers should come out.
Package tray or parcel shelf.
10cm
4.5"
Front Speakers: 6.5" Component system Rear Speakers: 6"x9"
You can typically put small, light items on a parcel shelf, such as shopping bags, a laptop bag, or a small suitcase. Make sure not to overload it as heavy items can obstruct rear visibility and become dangerous projectiles in case of sudden stops or accidents.
On my Pug 206 I had speaker terminations for rear speakers but no rear speakers fitted. I simply chocolate blocked each one to extend the speaker wires to the boot of the car. Even if you have rear speakers fitted it should still be possible. I've got a 3dr car, so it was fairly easy. If you have a 5dr you may have to try and remove fittiings to run the wires properly
Think you need to expand on what you wish to do.Corsa's already have at least a base and a treble speaker in each front door for the standard fit stereo. Most extra speakers are put into the rear parcel shelf,or a ready made "custom" shelf is fitted with speakers already fitted.You generally need an upgrade on the stereo to drive these usually powerful extra's. *Some Corsa's also have speakers in the side panels of the "boot".These could be used to upgrade one without them.
Remove the rear seat, it is held in with spring loaded clips near the front, just pull it up gently.. Fold down the back rests. You will see that the bolsters, the side supports, are separate, remove the bolt at the bottom near the floor, then slide it up towards the rear window, it will slip out of the retainer holes. Gently prise off the plastic trims from the sides, they come off quite easily. Undo the clips holding the rear parcel shelf, and it should be able to be lifted out. This exposes the speakers, as the speaker covers are part of the parcel shelf. You may have to get into the boot to undo the screws/bolts securing the speakers, from underneath. There is a good video on YouTube by someone called carolking67 or something like that, which explains the process very well.