hi! i am currently trying to install 2 12" subs in my car. i am uncertain how exactly to set everything up. what i would like to do is keep the stock amp and speakers independent from the new amp and subs. basically i was wondering if it is possible to connect both the stock amp and the new amp to a new head unit without touching the the stock one? if not i would like to just run everything off the new amp, how would i do this? oh ya i have a 94 530i. i appreciate your help!