Jinen

Does anyone know if there are any audio inputs behind the entire STEREO/NAV UNIT? if I wanted to attach an amplifier in the car to add additional subwoofers, then I need those audio inputs...otherwise there is another way that i can do, which is to spice the rear speaker wire and get a converter that goes into the amp so that way the amp can get power...but i'd rather go straight to the head unit...so has anyone seen any auxilury inputs behind the nav unit/stereo?