Bout to get the 50K service done by a mate on my 07 GTB 6spd and curious about what fluids (if any) must be replaced with the genuine Subaru ones as I have used the dealership twice so far and wont be doing that again.

I have heard that the coolant should definitely be kept Subie spec, but others (diffs, gearbox etc..) can be other brands...all fluids are replaced on this service and I would like to run the best for the car obviously, but I don't want to re-mortgage my house unnecessarily to pay for the service either!

I can't seem to find anything on the threads about the coolant particularly (sorry if I've missed a blinder) so comments, advice, past experiences and any other info would be much appreciated!