just had a thought, would be nice to see some leaves fall from the tree's onto the track during a race.. and while the winds are up, the more leaves there are on the track, on a peaceful day, not as many..
could even match this into some seasons, have Autumn drop heaps, and other seasons not drop as many.. also could have a clean racing line with a dirty track so its easier to see where the race line is clean and not so clean..