There are no cooling ducts for the brakes, but I have not sealed off the intakes above the splitter. They're big holes and no doubt contribute to front end lift and drag. It's another small thing on the list of tasks to complete before next season. Given the lack of brake cooling needed, I have considered covers on the wheels to make them flat like this:
Of course, I need to weigh up (pun intended, no matter how poor) the increase in rotational inertia and unsprung mass versus the benefit of reduced drag.