Chet's old z, the one that won the ARRC, had 2 ducts on each side of the air dam and 2 ducts attached under the bumper that went through the large center hole in the airdam. Totaling 6 ducts. I have a picture somewhere. The GCR denotes the ducts allowed in the airdam by total size. And the center section isn't really the airdam, its an existing hole. So they (Katman and Chet), had a duct for each of the 3 hoses that ran to the brakes. I don't remember if they ever got protested, or what happened if they did. The airdam ducts didn't go over the total allowed area for the airdam. As I recall. (I could be remembering wrong, and I'll try to find the pics)

Tom