Actually i did upgrade my speakers, or maybe i should say system. I originally emailed Mitsubishi if they would for me, but they wouldn't. So i found a local spot, that does it. I added a mono rockford amp, and 12 inch rockford subwoofer, but kept the stock speakers. To be honest, im blown away. The bass is quite incredible. Turning it to max, you feel it in your chest.
The best news was that the guy did not have to take apart dashboard to connect to the stock system, which i was worried about. Definitely worth upgrading. Cost me around 800$ in canada. I can post pics if anyone would like.