I just got my new Rspec delivered yesterday . . . . I really wanted the upgraded 6/4 brakes but the dealer basically talked me out of it because "it costs too much when they need to be replaced" and when I asked whether I could get some put on the car he said that you can't buy them as a spare part. As all the Rspecs were built already I didn't have much choice. Does anyone know if these are actually available from spare parts at all? What actually is changed? Is it only the rotors and callipres with everything else remaining the same? Are the brake lines, master cylinder or anything different? Would the AP racing 6/4 be a better setup? Basically what is involved in changing a car with the existing standard setup to the bigger 6/4 setup?