Just in case the info you find is for the early build e53...take note that the rear liftgate may be different due to the introduction of the soft-close feature. See the information below...again just in case there's a difference in how the liftgate reacts to manual opening.
And here's some tips to those reading this thread..there are 3 things you should learn to do so that you NEVER EVER lock your (only) key inside the vehicle & have to deal with the inconvenience & frustrationthe OP is having to deal with:
- always unlock the entire vehicle...even when only going into the cargo area
- NEVER lay the key down inside the vehicle...ALWAYS put it in your pocket' hold it in your mouth or give it to someone else outside the vehicle...but never lay it down inside..and if you follow tip #1...if you did lay it down and close the liftgate or door...the entire vehicle is still unlocked.
- always lock the vehicle with the key from outside the vehicle...which if you followed tip #1 & #2...you'll never be locked out of the vehicle