Two sources at the Morgue, Dave (RaceCars) as posted above or Tom aka Tom, F&L GoR enhances the rear brake caliper to a larger size. Check the Supplier's Section.
Additionally, on Paolo's Big Blue N White there are Bigger Brembos up front and the front calipers were moved to the back. This car not only stops on a dime...
It'll throw you through the front windshield!