MJ: that is because full CF will not buckle in an accident and slam through the windscreen.
I have a CF bonnet and love it, I have been pulled over twice and both times had no hassles, just questions.
I would go for carbon fibre, Might get someone to take a photo of mine this thursday so you can see how it looks, I also have a white 33.
They are only for looks, even real CF on a street car will save you max 6-8kg of weight, unless you are going for a sub 10 sec time, big deal. However my car does run alot coooler in terms of underbonnet temps due to the vents.
I got mine because it worked out cheaper than buying a stock bonnet an having it painted after my last bonnet was buggered.