The painted racing calipers I put on 2 cars (Cleo 24V and the RUF 3400S) cost $1500 per set. Gotta say, it does add to the look of the car. Great for those that like photos. Unnoticeable in a race. Too busy to look at your brakes.
Also, the Nissan Vision GT car has an active KERS system.
To use it, press the button assigned to NOS. (Gotta remap my wheel. I don't think I have a NOS button). It regenerates during breaking/coasting. It has 3 bars to indicate how much you have.
Some guys on gtplanet have said they ran it without knowing about it, then went back and knocked off huge chunks of time compared to what they previously ran.
Not all cars can have number plates. Looks like standard cars are out. Active list of cars being built at GTP.