Granny, what you want is the "body in white" racecar STi. But they don't make that. They used to do that with the SPEC C in other markets, stripped down to the bare bones, plain white, but had upgraded components. But I haven't heard of that in a while. Since most race teams strip out all the interior anyway, why not just offer it like that from the factory? I'm guessing that it's not a popular high volume sales item.
EDIT: I guess the body in white is just the chassis and body, no drivetrain.