I just purchased a 2010 wrx i've always wanted one but couldn't afford it till now. I want to increase the hp and boxer sound without voiding the warranty on my car. I thought about getting the staged kit from perrin for the rx but i comes with a downpipe which from what i heard is illegal in cali. So my next option i guess would be a spt catback, not sure which air intake that could easily be switched back to stock if need may be and a ap dunno which one to go with? Any suggestions anyone? keep in mind new to all of this so my questions might b pretty dumb. I'm obsessed with this car!