Nothing special to it, they designed it well which complements the design here just as well as any other truck. This is just an entry-level truck from Mercedes so as a work horse if you need it.... well, you need it!
I guess it was a design feature to help put focus more on the cabin than the rear end of the X-Class since they know for a fact that most owners won't be doing to many truck related things with this compared to people who buy F150s and the like.I do like that they added some character and flair to the side windows of that cover. They aren't just standard rectangle windows, they have a nice curve to them and work well with the lines of the truck itself. I would get one just to have in case I needed it.