Hi there here is it what you probably need
Cusco Diffuser Bracket Subaru
Cusco Rear Lower Subframe Bar Subaru
In USA this cost around $300 in total with diffuser
http://www.rallysportdirect.com/STI-...-STI-2002-2007
http://www.rallysportdirect.com/cata...ubaru+diffuser
Jura