I just finished piecing my exhaust together. I'm running stock cats, a resonated motordyne xyz, and the Tenabe medalion. For the intake, I have k&n drop ins and z1 tubes. It sounds great but there is a drone around 2.5k under load. A downshift fixes that right up.

I got it tuned, uprev, and I'm putting down 294 whp. My base with everything installed was 273. I know tp's will open it up more, but it will also increase the dB's. after installing the exhaust I did see a noticeable increase in power. I was surprised at the 273 base, but I'm happy with the car now.