Are those calipers cast or are they machined?
The fronts and rear red ones (parking brakes) are plastic, but I textured them to make them look cast and coated. (There's a company up in Washington that does the process in real life.) The rear main calipers are resin items I cast and treated the same as the others.
Each of the black main calipers has at least 20 metal parts in addition to the caliper bodies...
The rotors are machined, but notice the vent holes are different styles. Square for the fronts, round for the rears...
The hubs are machined, (aluminum, like the rotors), but treated similarly as the calipers to make them appear raw cast metal... - Mark