[RPhoboS]

I managed to get it open, not really sure how (was after a drive) - and took off the plastic surrounds to see if anything was obvious.
It seems more likely that it's the motor, as you hear it trying to unlock the first press, then after 2 or 3 more times it doesn't make a sound at all. If you wait 10-20 seconds and try again, it'll try and do the same thing.

I removed it, wiped up the plethora of grease and grime, put the latch in the lock position and watched what it tried to do when you press the button on the hatch. I can see it basically doesn't get enough power to unlatch, so I'm guessing that means the little motor is toast ?
(I can see 2 screws holding it in but I imagine there's not a huge amount I can do to it)
But perhaps the whole mechanism needs replacing?
p/n 30784739