okay this is just a general question. like say i wanted to upgrade a standard system i know i would need an amp and newer speakers but would i have to replace the old speakers throughout the car? like im saying if i wanted to add like 3 14in subs in the trunk would i need to replace the one that come stock in the car even though they are infinity speakers so they are not generic. also how does all of the wiring work? where do i hide the speaker wires in the door panel or what? maybe you can give me some general knowledge im interested . by the way im good with technical **** like i can rewire a house electrical stuff like that im smart with stuff like that but ive always wondered if the same concept applies to cars