The size of the carbon ceramic rotors has been increased to 390 mm from 380 mm for the standard metal brakes on the GT-R. This is one of the biggest cost increases on the car. The listed price for a brake pad and rotor replacement is $45,000. These brakes are supposed to be higher in specification than what Ferrari demanded for their supercars.
The overboost button is part of the cruise control button. It allows for 80 seconds of overboost in the midrange to increase torque. When its activated you get a little green turbo in the cluster.
New color: Ultimate Opal Black. The color resembles a midnight purple color. Kris says it changes color under lights from purple to bronze.
The carbon brake ducts in the front splitter are cute. They are fairly small to try and cool brakes that are stopping a 3700+ lb car. Its the thought that counts though right ?
Your $170,000 also gets you a cool carbon fiber key.