The NACA ducts in the aluminum part of the belly pan keep air circulating around the exhaust and rear differential to prevent heat damage.
There will also be a shorter length “Kurtz” tail that meets time attack rules configurations that will still cut drag considerably.
You can see the angle cut exit of the Blackbird Fabworx exhaust system. You can bet that the future diffuser will be blown by the exhaust for more downforce. The exhaust is fabricated from stainless tubing and has a Magnaflow straight through muffler.
The large APR barge boards keep air from spilling off the car's sides and curling under the car, improving the effectiveness of both the front and rear aero. The barge boards also recover pressure from the pumping action of the front tires and the side spill air for more downforce with little drag penalty.
The guys at Blackbird Fabworx know this and have some big tricks up their sleeve to counter this.
The honeycomb carbon deck spoiler also improves the airflow in the flow field under the wing and also will help activate the rear diffuser once it is in place. We think it will probably be integrated into the upcoming long tail.