They are not using full Carbon Fiber bodies, the main body shell is mostly Ultraglass, a new and improved form of fiberglass. Carbon Fiber is light and strong, but, it is a bit of overkill for cars that change skins so often, it is mostly used for doors, scoops, hoods and other interior parts. Top Fuel and Fuel Funny Car mostly use Carbon Fiber due to the stresses they face vs. a Pro Stock car.