It's already been in the dealer once already, for a leaking rear differential. That was back around last octoberish. Now it's for a weird knocking noise that comes and goes. Only happens when I'm around 70mph or more. Not sure if its me, but I swear when I hear the noise, I can see the hood vibrating, but never interferes with the actual drive (smooth & no wheel vibration can be felt on steering wheel.). The wife says she feels it around the passenger floor board. Car currently has 24k miles on it. Dealership mechanic was actually scared when he heard it, cause he thought a wheel was coming off. So he had his foreman go with him, and they think its the driveshaft. Was suppose to have it back yesterday, but never received a call. So kinda thinking its not the driveshaft like they thought.