Thanks for the reply, SlyCoopers.
I'm talking about the entire rear hatch...Haven't really examined anything else closely back there after I discovered, and knew, a paint correction on the entire vehicle would be needed anyway (black paint!). I didn't want to go ahead with the correction until I got the cause back there sorted as best as possible first. Right now, if you run your hand over my hatch it feels like sandpaper.
The previous owner took great care of it, but he didn't know how to wash and care for a black vehicle, unfortunately.
Its strange replying months later but I see what you meant now after getting a first hand experience driving through dirt roads in Vermont the other day I visited. Entire rear/window and part of the roof somehow was covered in dirt/dust especially considering the area had like some type of very fine sand laid down in the path. Weather was dry and wind was little to none. Yet Ive never seen the cx-3 get fully covered and dirty so easily in my life before and was definitly not expecting it so quick especially considering traditional trails and rock roads didnt cause this much dirt build up haha. I guess thats physics and air displacement for ya, unfortunatly mudflaps really do nothing for this :/