To be honest I think if he manufactured the carbon fiber splitter's.. the price would scare everyone away.
Carbon fiber is gradually increasing in price.. and a large MULTI-LAYER panel would be really pricey. (Starting from in front of the bumper, back to the front cross member) **eBay sells 65'' L X 18'' W X .0125" carbon splitters for $150 plus $75 for shipping**
Here is a general idea.. a local company has carbon fiber available for $50 per yard. that's 50" inches by 36" inches. Now one layer would be way too weak.. in fact it will flex.. ALOT. One good layer would be around $100~ish. Now imagine the epoxy, manufacturing, cutting, trimming, sanding, polishing would add more money. Now run several layers of it.. im sure you can add it up.
You could probably make several aluminum units for the same price.
if you like the look, maybe just cover the aluminum with carbon?