I drive a 2008 M5. I love my car, needless to say!! My car is still under warranty. Recently we've taken the car into the dealer (tried both of them in the valley) and all we hear from them is "we can't duplicate that sound", so whenever we tell them there's an unusual noise they always tell us nothing is wrong! So stinking frustrating!! I drive the car everyday and I know there are things wrong with it but the dealer keeps telling us nothing is wrong. What to do? Any suggestions?