I have two issues up before the service manager at the stealership where I got my 300C: 1) front tires feathering, and 2) 55-58 MPH vibration.
After several days of waiting for their alignment machine to be repaired, a re-alignment looks like it will finally happen tomorrow. What they will do about the tires doesn't sound good right now. Stay tuned.
So, as it turns out (of course) I am the first guy to bring up the vibration situation with my service manager guy. This morning when discussing the re-alignment he told me he had another guy just report the same vibration problem with one big difference: the car has a V6 engine, not the Hemi!
He will be looking into the other guy's vibration problem tomorrow and wants to hold off looking into my vibration problem until he figures out the other guys. He can figure out whatever he wants to figure out, but tomorrow he's getting a ride in a Hemi-powered vibrating machine, whether he wants to or not. I'm going to be there, and he is going for a ride!
So, it's not just the 300C's. I would imagine that all of the postulating on MDS, exhaust systems, and transmissions causing the vibration goes out the window because MDS only applies to the 300C, and the exhaust systems and transmissions on the V6's are all different too.
Tomorrow may well be an interesting day.