Those tires still have a lot of tread left. I think you should file a warranty claim through Continental USA.

I had a set of Yokohama on my father's 1987 Pontiac 6000LE. All four tires were cracking along the sidewalls. I call up Yokohama customer service. The service representative told me to go the local Yokohama dealer to have it verify. It gave me a prorated credit on the remaining treadlife.