If your buying from a Subaru main dealer and the car has had modifications,(i.e dump valve) fitted by a previous owner, make sure this is noted in the warranty handbook.
As once you leave the garage and something breaks they WILL NOT honour the warranty, p**s you about for 2 weeks then bill you for £600 to get the car back in a millions pieces worse than when it went in.
p.s. 2005 Hawkeye STI For Sale, bargain price as I havent used it for months being overseas.