Audio Systems: pontiac monsoon add an amp and subs easily?, grand am gt1, monsoon system

Question
Ive got the monsoon system in my grand am and i want to add my ampand subs for some extra kick, i would also like to put my sony deck in. which after reading some of ure posts to other people it may not be worth it i may be better off leavin the stock the way it is. Whats the best way for me to hook up my amp. i would rather not use the hi-inputs on the amp, ive tried them b4 and it doesnt do that well opf a job. so i would like to use the rca's if possible without replacing the head. Thanks in advance for your help. 2003 grand am gt1  (sc-t version)

Answer
Without seeing it in person, I can only give you some basics.
The head unit should have a line level output.
If you can get some info on the head unit, you may be in luck.
Interfacing may end up being quite a task, so you may want to check out crutchfeild.com for more info about that.