Hey guys, I have a small 10" sub & box sitting around in my garage. Since it's a single sub, I thought it would be perfect to drop into my trunk and connect it to the factory amp in the trunk. Of course, I will be disconnecting the factory sub. I just want a little more bass, than the factory sub can offer. I already have a nice aftermarket headunit. My question is: Has anyone tried this? Should I use a 4 ohm subwoofer with the factory amp? I just don't want to blow the factory amp. Thanks!