Of the many auto-inspired photographs in this challenge, this one best uses space, color and form to express the kinetic energy that is associated with cars. That subtle little arrow is so cool as an indicator that this bad boy is about to GO! Watch your feet and hands, please.
For those unaware, those brake rotors are made of a ceramic composite, not metal. Caliper and wheel are both definitely metal :) I assume that the car was a Porsche Carrera GT? A lot more fun to drive than to photograph!