Fuse your main power cable close to the battery. Within a foot or so. You should be fine going through the sound dampening. I screwed my ams right to the floor under the seats and never had a problem. If the rcas are directional make sure to pay attention to the arrows and which way they are supposed to go in. It wont matter if the + wire is near the chassis. I dont see any way how you could possible have it far enough away even if you wanted to.