More to add on aeroscreens. They produce a bubble of still air, so, the height and shape of screen that best works for you will depend on how high your seats are and how long in the body you are, which both affect where your head comes to. Seat rake angle also affects this and can be altered too by angling the seats, but the scope for adjustment is more limited in a Westfield. Can't tell from your avatar picture, but if you have a lip style aeroscreen already, but if you do, then have a drive at speed and feel with an un-gloved hand where the still air ends and where the wind rush starts on the passenger side. This will give you an idea of how much higher the screen will need to project, or alternatively, how much lower the seats can be dropped, or raked. You'll still have to be able to see over the top of the screen in normal driving.
Jen
Edited to add: There is a new thread on Tech Talk about aeroscreens for people with their heads in the clouds.