i was just messing with you, i know how much hp your car has, and when you post something like "i want dual exhaust on my matrix!" it sets something off in my head "RICER!" most people do it, and it looks like ***. i just hope you don't do it, and it looks like that. you said you wanted dual exhaust to get more performance out of the car. if you want that, you're better off getting forced induction.
an exhaust alone won't do it for you, specially not on a matrix. all you'd get is an annoying loud sound coming from your car and less torque.
i've only had 7 posts, but that doesn't mean anything, i've been on these forums for over a year, just never registered.
in conclusion, your car has 130hp, it won't go much higher unless you spend big bucks.