Guys
When did you change your GB oil last and what type of oil is in it now? I am no expert but if you don't know the answer to both of these questions its time to change it.

Go in to your favourite reputable (non Subaru Dealer) Service workshop...as I am sponsored by Exleys Tyre and Brakes I will insert sponsors name...now and let them tell you what you need.
Did I mention they are in Willeton...

other reputable options and in no particular order to keep you oiled are:
Maximum Motor Sports/Nth of River
Tenagah/Nth of River
Race Torque/ North of River
Flood Motorsports/South
RMS/South