Awesome ok, I kinda figured it out after reading it more but you guys explained even better. Basically it's great when you've kept the flywheel in motion.
So it wouldn't be worth it's weight on a street car? That's something that still remains to be seen. Skip down to the 4th paragraph if you want to get straight to the point of me including this link:
Formula 1 hybrid technology: high-speed flywheel energy recovery systems ready to hit the race track also may be coming to the street. - Free Online Library