I have the same problem

Usually there is a bar between the lock and the latch.
If the lock is broken and you can gain access thru the back seat, you should be able to take the bar out and turn the latch with a screwdriver.

Enter into the trunk space after folding the rear seatbacks down. Pull the yellow emergency trunk release handle that should be dangling right beside the area where the trunk latches to the car. This should get the trunk open so that you can expect the locking mechanics for damage: bent steel, something foreign stuck inside, bad cable, etc.

WHEN YOU SAY THAT THE TRUNK WONT OPEN, DO YOU MEAN FROM THE INSIDE OR THE OUT?
WELL IF YOU CANT OPEN THE TRUNK FROM THE INSIDE. TRY OPENING IT FROM THE BACK WITH THE KEY. ONCWE YOU OPEN IT LOOK WHERE THE TRUNK LID MEETS THE CAR WHERE IT MAKES IT S LOCKING CONNECTION. ON THE LEFT SIDE THERE IS A MECHANISM THAT YOU PUSH IN SO YOU CANT OPENING IT. JUST PULL IT AND IT WILL ALLOW YOU TO OPEN THE TRUNK FROM THE INSIDE. GOOD LUCK.

i'm not 100% sure with that vehicle, but you might be able to remove the back seat to gain access to the trunk

you need to have the trunk open and the lock unlocked first then you can get the barrel out of the lock and remove the broken part of the key,,,so dont lock the trunk till you get it fixed,,,

think you might have to go in through seat to release it ,something broke inside the boot lid ,last one i done it was the piece that pushed the release mechanism inside on the lock

I have the same problem with 94 Cadillac, trunk is locked and can't open, cannot get rear seat back off, any suggestions how?

you can open it with a key? right? if so, sometimes there is a "lock out" lever near the trunk latch, the owners manual can show you where it is and if its in the locked position, it wont let the trunk open. The reason is.......if someone broke into your car, they cant just open the trunk.

All newer vehicles have an emergency manual trunk release inside the trunk.

This should be basically a rip cord directly attached to the trunk locking mechanism. Most modern ones have a yellow handle on the ceiling of the trunk that will release the trunk latch if it is pulled. Yours may be a different color, but if you get in there with a flash light you can probably trace a steel wire from the trunk latch back to some sort of handle that looks like you can pull it. Its definitely worth a shot.

if the doors and trunk are vacuumed operated, make sure all the doors are unlocked..this might make it easier to open the trunk..or get the car running and then try to open the trunk with the car running..turn key all the way to the left and push slowly in..I think it is vacuum operated like the mercedes