https://www.cnet.com/roadshow/news/2019-ford-gt-carbon-series/

Instead, the Carbon Series equips your Ford GT with carbon-fiber wheels, titanium lug nuts and a titanium exhaust as standard. Those parts were already available as options, but the Carbon Series bundles them into one package. The rear hatch is also different, using a polycarbonate material and featuring more venting for the engine. Moreover, Ford says that engineers removed the GT's cupholders and the driver's-side storage bin to reduce weight.

Carbon Series cars come with an unpainted center strip that shows off the carbon-fiber weave beneath a protective glossy layer. An optional accent package (silver, red, orange or blue) draws a thin stripe down the middle of that stripe, with matching accent-colored exterior mirrors. Inside the cabin, look for special Carbon Series badges and various red accents. Overall, Ford says the Carbon Series has more exposed carbon fiber than any other version of the GT.