My Proace a small dent, on fifth door, directly on the line..
So i decided to try to fix it myself..I did remove the cover (spare fastener clips needed 
I found out that alle support beam are not glued to outter shell anymore. They used some black hard substance..Not sure if they torn away because or the dent or from closing the tailgate with the rope..Anyway fixed it with SABA flexible glue
Closing tailgate sound now better, does not have the very metalic sound. And yes ti managed to fix the dent