I had that droan on mine. Took it in to the dealer with photos and write up from a post on this site about adding "dappeners" to the exhaust downpipe before the CAT and the sound is now gone. That droan was just driving me crazy for the last 33000 km's. Do a search on "dampner".Now if they will do something about that droaning sound onthe highway. They replaced most of the exhaust system and the noise is 50% gone but it is still evident.