I have an 04 impala, I have been hearing this really odd sort of like chirping noise when going over rough spots, pot holes and such, it just sounds like my exhaust is banging up and down. so I took my car to the exhaust shop, not once but twice, they assured me my whole exhaust system was tight and fine. I then replaced the rear linkage and rear brakes and rotors. However I still have that annoying bang/chirp sound which sounds like it is coming from the back of my car any suggestions??