In my opinion, using a CF driveshaft in these cars is a bit of snake oil.
Benefits of a CF driveshaft on real cars: lighter, less flexing
Sure it will weigh less than the stock steel shaft, but in proportion to the overall weight of the car, will it make an appreciable difference? Very doubtful. As for rotating mass (bringing the shaft up to speed), again, the difference is not appreciable.
As for flexing, the tiny motor doesn't put out nearly enough torque to twist the stock steel rod.
So unless someone has some decent empirical evidence that the CF driveshafts are useful, I'd avoid them.
