You can do anything allowed in Sport Category, so there are a few allowances there including adding some trim.

In addition to Sport Category allowances, you can use an aftermarket hard top - including those of carbon as long as it's an exact copy (no aero advantage from stock) and uses the factory latches. You can also remove rub strips, replace pop-up headlights, roll your fenders and add commercially available bodywork molding, trim, and other appearance modifications including flexible “chin lips,” which don't affect performance or reduce the weight of the car.