Rich,
Very good question.
It all comes down to space to make the AutoCross a great part of the event. Rhinebeck has very little pavement and if weather is an issue we could not be taking up the area with the AutoCross as we would need it for show car parking.
Charlotte and Columbus are going to be your closest at this time. We add events when we find a good place to have them so stay tuned and we will see if there is anything coming your way.
Goodguy Ed