I have a knock noise ...a single knock when changing gear at speed.
sounds like its something under the gearstick
(novice with subarus) but rear of gearbox knocking on transmission tunnel?
dosnt do it driving in a calm and normal manor
its a 07 hawkeye wagon

 

Hi Nick, did you get anywhere with this fault? i have just noticed something similar on my 2004 STI.

 

The stock bushings are very soft and you can get some noise like that on an agressive gear change where the clutch is released quickly.

 

Outrigger bushings.

 

+1