Hello again, sorry I was still logged in but not at my computer.

The usual fault that causes this concern is the tailgate latch itself. To open the tailgate requires damaging the latch, you need to cut a hole in the plastic and release it. Below shows where you need to cut, there are a couple of style latches so I'll include both.

number 1 is a new style latch, the arrow shows where you need to cut the plastic number 2 is the old style. I suspect given the age of your car that it will be an old style latch.

If you can access the latch then you need to cut as shown below and release the latch.

If you can't access the latch then you need to remove the scuff plate along the boot floor and unbolt the latch striker, the tailgate will then open with the striker still attached, you then cut the latch and release the latch as shown below.

Cut as shown above and release with a screwdriver as shown below.

Obviously to access the latch to start with you need to fold the seats down, also before doing this make sure you have a new latch to fit.

Let me know if I can assist any further or if you have more questions.

Best wishes,

Sean.