The Mercedes dealership who fitted my bed liner advised that the water and dust kit was incompatible with the bed liner. They claimed the seals either side of the tail gate was the cause of the bed liner two-sided tape detaching from the body.
It appears M-B hasn't issued any advice to the parts suppliers or their customers to this effect and are happy taking the money.
Interesting that the sports canopy comes standard with the dust and water kit. So what if the bed liner is fitted when the canopy is ordered?
Feeling ripped off.