[ctuna]

You are correct in assuming the passenger side is the noisy side of the
car. Yes you run the power wires directly to the battery for all your aftermarket stuff with a fuse. There is some debate at to how noisy the
chassis grounds are. One of the professional installers on this board suggests
running both the power and ground directly to the battery and since I bought his kit that's what I did and I don't have any noise. People that have used the other grounds have had mixed results. I think you only need to follow the existing wire routes to get good results but I guess is you started out with a base system they might not be there. I think most are buying the Technic Harness and he has a route plan with that. If you look in the Audio Contents
thread there should be some examples.