I just added an amp and sub to mine. To use the factory radio with an aftermarket amp, you'll need a converter for your factory radio so you can plug the rca's from the amp into it. I got mine from the local audio shop for about 20 bucks. It's pretty easy to do. The whole center of the dash (vents, HVAC controls and all) pops off, then take out 4 screws and you got the radio out. Splice the converter into the rear speaker wires on the radio harness. You can find the wire identification colors on the internet.