was there ever a fix for this?

Because the door post/ upper anchor is so far back the shoulder part of the seat belt digs in during long roadtrips

 

Our 02 C230 coupe is my wifes and she doesn't notice any problem so she didn't want a seat pad (which is a good fix). I use the cheapest dumbest solution in the world. I figured out where the belt is the most comfortable and use a clothespin on the upper anchor to stop it from retracting too far. I placed a tiny white dot on the belt where I put the clothespin. Works perfectly for those times I drive the beast and doesn't impact on the ability of the belt to retract further in the event of an accident(clothespin will harmlessly fly off). I keep the pin in the centre console.

 

Good idea, I'm not a fan of pads in a Mercedes but I like the sound of the clothes pin except the faff of adjusting it for each person that uses the seat.

I have a 600 mile road-trip to the parents each month, that when it's worse.