No need to replace the OEM coils unless you have a problem. Most people move one or two heat ranges colder on the plugs depending on driving habbits. There is also no need to go to aftermarket plug wires. I had MSD ones and went back to OEM ones and saw no performance decrease. I would howeve recommend that you do at least get some fresh ones on there every 30k or so if you are looking for the absolute most out of them no matter which ones you put on.