Well i thought i would post in here and give you the benefit of what i found out today having been along.
Luffield A and B are open, round to farm and upto club corner. Some excellent shooting positions i thought, between myself and my mate we shot over 20 gig of images by lunchtime. Most of the teams were there although certain drivers are only there on certain days, i can remember which ones unfortunatly, it was announced over the circuit tannoy.
Hope this helps people
Also 200mm is more than enough around luffield if you creep upto the mesh fencing when the gestapo are not around and also more than enough around farm and club.