I have a 2012 traverse LTZ that has a heavy vibration at 1000 RPM very annoying and felt have taken it to the dealer to ck they said this is normal noise. You won't believe this but the mechanic told me if I want to get rid of the noise I should put a after market exhaust system on it. I asked if they are going to pay for it and I did not pay $44,000 for a noise maker.Just wondering if anybody has heard of this before.