I think there's some confusion here over the use of the word "carbon". Some supercars & a lot of racing cars use carbon ceramic discs; however, at £500-plus for a disc I don't think they're a viable option for your Spider!
"Normal" brake discs are made of cast iron. All cast iron contains carbon, in the form of graphite; some manufacturers offer high-carbon CI discs, which have a higher carbon content than normal, along with other alloying elements. They are claimed to offer be better in high-performance applications, mainly because of improved thermal properties.
Last edited by Dave Brand; 06-01-16 at 14:40.