Electric components not working

What terminal or fuse did you connect the amp to in the rear box? Can you still start the car and does the horn work? Asking because those use the main power feed to the rear fuse box as the lights and wipers. That vehicle has multiple power feeds that are controlled from the front control module and the FCM in turn is controlled by other feeds. Knowing where you connected would save time in tracing if it's a fuse or if it damaged the CCM or the actual fuse box was damaged.