Do you get more or less spray/misting as you speed increases?
Good question: I think it gets worse with speed but need to find out. Rain is forecast today so will go out this afternoon after work and see.
Clearly from what others have reported the way airflow varies from car to car so the dirtying if the inside of the screen is something of a random occurrence.
On Tarka the back deck of the car gets filthy as does the rear of the hod if it is up. The roof stays clean!
Yesterday I drove with the sun visors swung up so that they were almost vertical: going through a wet patch on the road it seemed as though they stopped the water getting on the screen, but not the mirror. This suggests the issue is more complex than I thought.
I’m going to try the rear mud flap route before doing anything else and then may see if fitting a spoiler along the top edge of the rack and see what the airflow is like along the top of the screen is doing, as has been suggested with woollen tufts.
I’m beginning to think that the presence or absence of crud on the inside of the screen is due to the interplay of two sets of turbulence, that from the flat screen and the vortex from the rear of the car. It is also worth note that the top of the box sections between seat and door get covered with road dust when driving; I cleaned and polished them last week and after a drive yesterday they were dull and gritty again.
So it is all rather difficult and the answer may well be a couple of micro fibre cloths and to enjoy driving, not worry about it.
