I'm in favor of doing away with the VIN rule. I would love the opportunity to cheaply upvert (wd?) my ITC ride into an ITB car... I'm already out qualifying several of those cars on the grid only to be passed later in the race.

As for adding a sunroof, only to deleat it later... that's wasted money and effort. If the car makes weight, does it matter? In fact, if the high centered additional weight is the concern, then a stipulation to add weight up high could be added.

Nontheless, going and racing ITB would only add about $1500 expense to my already built car... vs building a new one for $7000 or so.