I get it Peter in my 2014 4/4. I used to get it in the roadster but not so badly. I wonder if it's to do with the curved bit that houses the reversing and fog lights.i keep meaning to fit something to the rack to see if I can change the airflow. It also coats the back of the headrests. It's definitely from the back as I once drive on a dry day through a deep roadwide puddle at 40 mph and the water just cascaded over me and the screen from behind. I must fit some mud flaps and maybe a solid plate on the bottom of the luggage rack would help?
Nick