Stevo, do you ever clean and check for built up mess behind those mud flaps?
I just ask as we had a convo on another forum about the benefit of mudf laps bar the disadvantages.
I personally think they suit the touring, so have opted to keep them, but I did find rust had started to develop where they fit against the bodywork. I have since removed them, rubbed down and treated the area, before replacing them.
I don't think just jet-washing alone is sufficient on an E30, and maybe a quarterly removal of the wheel and thorough clean out under the arch and behind the mud flaps is needed.