Have 2015 stingray 2lt none z51 package auto a8,zf1,mmp exhaust.when driving in 6th,7th,and 8th gear around 1500rpms i get a vibration howling noise coming from the rear area,does it more on flat driving area. Sometimes up and down hill but most of the time on flat roads, have taken to one dealer now and they don't know what it is and cant find the problem and yes they can hear it and have driven other 15's to see if they all do it and they dont, so they are stuck and just say its normal for the exhaust i have.
Also the rear end is clunking in slow traffic. Also telling me this is normal.
Do have a case # and taking it to another dealer tomorrow so we will see what they say.
Have found one other on here with the same problem as mine but his is not fixed and looking for someone that knows of this issue.