Hi Ant,
The aero screen worked out fine. I did the angle across the bottom out of a strip of aluminium sheet bent at 45 degrees. I worked the curves into it using a shrinker/stretcher machine I bought. I cut the screen itself from 3mm Lexane sheet because it's shatterproof.
This is my first atempt and Im working on another one. The next one will have a little more rake and will also be curved back towards the ends. It was quite effective on the track and took the wind blast away. You would still need to wear wrap around sunglasses to keep the dust out of your eyes.
Cheers