I do not believe that car sharing or double dipping is a good reason for DCs but I know it will happen and it is not a reason to not allow DCs. The question to me is would there be a down side to tweeners being Dced.

What will be interesting in the SM world is if with the class being national will there be less big money cars in regionals? Also while you can spend big money to build an SM, I think they are still cheap to race not counting body repairs.