I am new to this forum with this being my first post. I am currently in the market for a 2015 200 C AWD, 3.6L V6. Just test drove one and WOW what a car! HOWEVER, when accelerating but mostly when vehicle would downshift, there is an audible growl or low whining noise. There is no "clunk" or anything else. I'll admit I haven't spent a lot of time searching too deep into the forum but was hoping a veteran can steer me in the right direction. The vehicle has 125,000 miles on it. The dealer said he is taking in to a shop next week for diagnosis (he is a small town guy so he does not have equipment/knowledge to do it on his own). Any other feedback or issues I may need to look for would be greatly appreciated!