it may have a separate feed or pin available for any factory sub upgrade which will run off the stock amp usually as they are usually only a very low power, if your going to install a factory sub then you might be able to get away with abit of a route around for a feed, if your are planning on putting a powerful sub and amp in to rattle ear drums you’ll need a low line converter and take a sound feed from a stock speaker for your sound, wire the remote wire into the ignition for the car or power supply for the radio as long as the radio turns off when the car is off, and put power and ground in usual places.