Why carbon?
I personally think it's a waist of money to use on a street car. I have witnessed 2 benefits when using a carbon shaft. When they blow up, they don't kill/injure you and don't destroy your car. Second benefit I have seen is it does help a smaller tire on the hit. The shaft will actually twist a little to absorb some of the hit and unwind itself was you start moving.
How much trouble would you think that I would be in to run this on the street?