I want to keep my factory headunit, and simply replace the Monsoon speakers. I have the 9-speaker system in a GP GXP. I know everyone will say to get a new HU, and a new amplifier. However, does anyone have experience with this? I've been doing some research, and Infinity makes some 2-ohm speakers which seem like they would work since the amp is 2-ohm. If I did this, should I disconnect the tweeter from the rear speakers? Also, if anyone knows the part numbers for the stock rear Monsoons I'd really like to know! I know they are on gmpartsdirect somewhere. Any help is greatly appreciated.