Ive got the flowmaster 50 muffler only, its then welded to the stock rear piece. Its loud when are you WOT, has a small drone on the highway but not annoying and you can hear when the MDS come on. I like the sound it makes not to much but I will be doing a straight pipe from muffler cause I want it to be loud. Keep in mind I have the intake on, before it wasnt as loud as it is now. Honestly if you arent on the throttle much like I am you wont notice to much of a difference.