Brakes were feeling increasingly worse since the first track day. Lots of vibration, especially when hot, and more noticeable in the afternoon than the morning for some reason. Maybe because it's hotter? This was present even without hard braking. I think this was because I did not resurface the rotors when I warrantied the Hawk pads for the ECS pads, since I noticed some vibration during the bed-in procedure for the EBCs.
Replaced with a fresh set of Zimmerman blanks and EBC BlueStuff. Also added brake ducts from the RS3 since that should help a lot with brake cooling on track. I noticed that the front left inner brake pad was a lot more worn and had cracks in the friction material, possibly from the vibration.
The vibration also caused the spring retaining clips to compress, which resulted in some pad clunk over bumps, though not as bad as with the Hawk pads.
During bed-in (part 1), the pads already feel much better, with no vibration noticeable.