I really appreciate the cabin in this GLS however I have noticed that this vehicle in particular suffers from the squeaks and rattles that so many complain about in newer MB’s(and probably other euro marquees).

Stage 1 of solving these annoyances was to start at the worst offender, and for me that is as soon as I interact with the car. The door handles. Every time that I grab the grip on the interior door trim I am surprised with how much creaking of plastics I hear and feel. It doesn’t phase my wife who dailies the car, but I can’t stand it.

Tonight I got intimate with the workings of this x167 and learned how to remove the door trim and chase down these squeaks.

The trim comes off with only a flat pry tool or butter knife. I think a flat blade screwdriver would risk damaging the edge of the plastic trim.
Once the trim pieces were removed I cleaned them and then applied Shin-Etsu silicone grease that purchased at a Honda dealership years ago for lubricating squeaky door seals and sunroof mechanisms for another car. Using a small 1/4in paintbrush(ie for watercolors or modeling) I applied a coat to all surfaces of the clips, tabs and edges and contact points. I also removed the window switches and coated the barrel of the switch.

I have to say that this made a HUGE difference in eliminating the noises when interacting with the door. The door now not only looks lovely but it feels nice to the touch and is quiet as expected. I also used spray silicone to dribble lubricant along the interface/gap between the door card and the door shell. That was also a squeak generator. No more.

This takes about 20min per door.
lower trim remove towards the front of the vehicle and the window switches trim removes up, pushing from below once the lower trim is out.