In my 2002 Grande Espace, there was no facility for a screwdriver to poke in and free the rear lock.
AND... the fastening screws for the rear panel cannot be reached with the door shut. What a truly stupid design.
Last winter in the cold, the lock seized and I had to wait for warmer weather before I could get the rear door open. Once I got it open I took the door panel off and cleaned and oiled the lock with silicon
to free it up, but to make sure that I never got stuck like that again, I cut a 2 inch circular hole in the back panel, over where the lock is and then covered the hole with a 3 inch disk of thick rubber and 3 self tap screws.