I got a 2008 dodge charger 2.7 v6 and i want to add a little more horsepower sense its such a heavy car and make it sound more rough. So i was thinking about adding some duel exhaust to it rite now and headers. Do i have to add headers and exhaust at the same time when i mod it or can i do them one piece at a time? Im not really wanting to add a super charger or turbo to it until i end up getting a different charger with a bigger engine some time from now. So whats a good mod to my charger, roughly how much will it cost, and the questions about the exhaust and headers i asked as well.