I created an account just to reply to this thread. I drive a Ford Focus ST with the RS Brembo front calipers installed and used the Centric high carbon rotors (both when it was the stock ST calipers and with the upgraded Brembo calipers). At my last track day at Blackhawk Farms I had a front rotor snap in the exact same place as yours. I was coming into turn 6 at 90 mph, hit the brakes, and BANG! Braking didn't happen and I skidded off track. Once I got back into the pits I found my rotor broke like yours, only mine got wedged inwards. This was a new rotor with about 120 minutes of track time on them. I've been trying to get in contact with Centric for the last few weeks with no luck. Just wanted to chime in and make this post in case anyone else ever has a similar issue.