Last year, I arrived at Prescott about 9.15 am with the rest of the ordinary public, queued for about half an hour to get in, then queued again for nearly an hour for sign in! It was horribly tedious but I still got half a dozen runs up the hill in the morning session which made it worthwhile and more than returned the smile to my face!
I intend to get there myself at about 7.30 (its less than 20 miles for me) on the basis that if there's queueing to be done , I want to be at the front! Also, since i'm sort of organising the TDC effort, it behooves me to get there first!
Shelsey works a little differently to Prescott, in that Shelsey has no return road which means that you are stuck at the top of the hill while up to 30 other cars come up, then you all go down in convoy (slowly)and the process starts again. This may have a bearing on how many runs can be got in in a session by any individual but I will be a bit ticked off if I don't get 3 or 4.
There is also, as always, the possibility that some moron will hold up proceedings by marrying his pride and joy to the scenery. Apparently, this is more likely in the afternoon session when folk have had time to get cocky. At Prescott they dealt with these incidents promptly and efficiently. Shelsey is more difficult logistically and the possibilty of a spectacular off is greater but I don't expect their marshalls and crews to be any less professional.
As the fine print always says "motorsport is dangerous"
Steve
EDIT, the bit about being stuck at the top is not as bad as it sounds, your granny in her Skoda (or Philip Glenister in a T seies MG) could get up Shelsey in just over 1 minute, a good time is around 40 seconds, so cars will be starting at about 30 second intervals meaning the wait at the top will only be a max of 15 mins.