Hello & welcome,  
I got one for a 'classic' impreza so working along the lines of the same year impreza stuff crossing over I'd hazard a guess you'd need a new age impreza one, how ever I'm sure I've seen someone with a fsti who's on stopper no3 as the previous two haven't been correct,  
I got a tegiwa branded one,  for about 35notes.almost half the price of the cusco and cdf ones and looks identical to the other brands   
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