Tell the service manager that maybe his hearing is not as acute as yours. Determining the level of the noise is somewhat of a subjective task. Unless he can show a DC tech bulletin showing that he noise must exceed a certain dB level before the part must be replaced, he as no cause to deny your claim. Bottom line is that if it is a problem for you then it should be addressed by the dealer. That's called customer service.

Sad to say it, but my Crossfire is my first & last Chrysler product. I can't buy another vehicle from a company that has such a p!$$ poor corporate culture.