I'm a new member, thought this would be a good place to get answers to my questions regarding my 2007 Chevy Cobalt. I have been very happy with the car, but I do have two intermittent problems which I would like to get to the bottom of. First, immediately after starting the car I can hear and feel a slight clunk(best way I can describe it), in the engine compartment, seems to be in the engine or drivetrain as if something is dropping into place, only happens occasionally but if there is a serious problem I would like to address it before the car is out of warranty. Second is a problem with the rear brakes locking up after the emergency brake is released, this happens both in the summer and winter. When it happens I have to rock the car back and forth to get it to release. The dealer resurfaced the rear brakes but it is still doing it occasionally. If anyone has any feedback on either of these problems I would appreciate their help.