I'm looking for some feedback about exhaust options. I'm pretty happy with the exhaust sound on my 2005. It has a nice rumble and burbles and pops when decelerating. what I would like is a cooler temperature in the car. If the car sounds a bit louder that's a bonus. From experience, have you noticed a difference in temperature with just a cat-back or would I need to replace the cats and headers as well? I don't want to get too loud (complaints from my wife). Any thoughts?