bose system

is it possible to put subs in a car if there is already a bose system in it and if so is it complicated

Yes you can add subs. You will either have to change out the head unit (using a bose adapter wire harness) and adding an aftermarket amplifier to the new sub, or you can keep the factory unit and use a line out converter to get a signal to an aftermarket amplifier and sub. Depending on the vehicle you are putting it in, you may need to get the signal for the line out converter at the subwoofer of the bose system, as some of the systems dont allow proper crossover points at the back of the bose radio. Some bose adapters are pricey, but you should use them. Make sure to deal with a local shop that you can trust and they can assist you with your new venture. Derl