I have the same issue Peter. My 4/4 has a coating of muck on the inside windscreen and dash. It can be cleaned off quickly but is a pain if you have been out all day and drive home in the dark as oncoming headlights make it tough to see thorough a dirty screen. One of the peculiarities of aero dynamics I suppose. My daughter was amazed to find her hair blew forward when we were travelling hood down. I don't have enough hair to notice