No idea about the paint, I saw some down halfords that might be of use. I would think if anything went wrong with your brakes and you painted it yourself that they'd wag the finger and say no you're ****ed.
The only way I can think of definately keeping your warranty would be getting the Seat Sport AP racing calipers that are on the Cupra and getting Seat to fit them, which would cost stupid money...
The only way I can think of definately keeping your warranty would be getting the Seat Sport AP racing calipers that are on the Cupra and getting Seat to fit them, which would cost stupid money...