I've looked at my HR-V and there are wheel arch liners (front and back) which might be bitumen-impregnated felt or something similar. The material contains some corrugations which, I suspect, are to improve rigidity. I doubt if spray reduction is one of the objectives.
Also, I've noticed that the most effective spray reduction measure for lorries is to provide covers on the outside of the wheels which stops the spray spreading out sideways 2 to 3 ft off the ground as this is the zone which messes up the car drivers' view.