I don't think he is brilliant. The hundreds of skids marks in most shots show lots of practice. How's his wrc record? I'm sure there are plenty of drivers who could do what he does.
How deep are your pockets?
http://www.subaruwrcspares.com/8.html
Scroll down that link and there is a real or replica. Another option is to get an sti spoiler and Perrin wing stiffies.
Yeah it was N555BAT that was used. The owner has replied to a thread on scoobynet and added a link to his flicker account with some pictures from the filming.