I had straight pipes on my 3.0. There was a noticable growl upon startup, and also to about 2500 rpm. After that, I did not notice a difference from inside the car. However, when listening from the outside, it does sound a loud louder. I did not like the straight pipes because they shook the stock mufflers and tips roughly. Also there is a lot of exhuast coming out, and so the garage would always smell. Standing behind the car, I could feel the exhuast about 3 away, pouring out. Eventually I put on the stock resonator. I felt like I gained more power when accelerating.But its up to you.