Painy is correct in that having open practice on the Thursday will completely remove the benefit of a three day race. Anyone who intends on having a really good performance must be there to get all the track time they can get.

Racers are already voting with their feet. There have been an increasing number of racers missing Thursday (and in some cases Friday as well) due to time/cost issues. I'm in the handbrake/wheel chock category and it is difficult to attend as many events as I would like when it means I have to sacrifice holidays with my family. Three day events would allow me to manage both a little better.