I'm new to the wrx world, just bought an 07 sti and had a few questions. I bought the car used and it already had the spt catback exhaust, intake and heat shield installed. I was wondering what parts will mate up properly for a stage two kit. After reading some threads I was wondering if anyone has the invidia v3 downpipe with the spt catback and the cobb ap. Does this setup sound like it would work and if so what numbers could I expect. I would like to be sitting around 300 whp. Any suggestions???