Yes happens regardless of whether brakes are applied or not. Noise occurs randomly while driving on any flat road or any other type of road, bumps do not matter, in fact bumps may shut it up. My tranny has been ruled out, so now I'm thinking possibly CV axles? 123k miles, all maintenance done, fluid flushes etc. I've maintained this car like an obsessed freak.. if that helps you. Little rust underneath, no rust on the body.