Do you have Beats Audio? If so you'll want to tap one of the rear channels for sound because the fronts run a factory crossover that limits their range. Best bet would be to find a full range source and use the powered sub to adjust the cross over point. Also I would always recommend running a fused power wire from the battery. It may be more work but it won't put any strain on the factory wiring. The amp may have a remote turn on via the high level (speaker) inputs. That can work well instead of running a remote turn on from the head unit. Any route you take I think you'll find it'll sound better. Not window shaking bass but a fuller sound. Best of luck.