How to open the boot (trunk to you americans, I think) on an australian mitsubishi 380 from inside the car?

The key works fine outside the car.

There's nothing wrong with anything that I know of.

We just can't find the button or switch or whatever that you're supposed to use to open it from inside. I assume there is something?

 

If you havent got this sorted from memory mate there is a button inside the glove box at the top, by the latch that it closes on. Hopefully this helps.