Picked the car up today. They replaced the driveshaft assembly - the center section is not serviceable. From the research I did on this, this is about a $2,000 repair, and looking at a few videos, I would say this is a known defective design & that ALL Chargers & 300's will need the driveshaft replaced, so BE AWARE & LOOK FOR THIS! My car has 70,000 miles & I would estimate I have been noticing the shimmy & something strange feeling & sounding from this for 5-to-7,000 miles. There is NO WAY one of these driveshafts could go much longer than this without a major issue!

Check this out:

https://youtu.be/jqG-EmL-Wzk