2nd Drive Shaft Replacement at 10K Miles

[chemi19]

It all started when I noticed a slight vibration on the rear view mirror at about 3K-4K miles. It was bad enough that at night time all I saw was a blur from headlights behind me. I took it to the dealership and of course first they said it was normal. After I told them that it was unsafe to drive like that when you can barely see the cars behind you the dealership decided to check it out. They first tried to tighten the rear view mirror, no help, road forced balanced the tires, no help, new front tires, no help. They gave up and again said it is normal, so we took a brand new Z and test drove it, no vibration whatsoever. I had given up on that dealership by that time (since they scratched up my rims while doing all this).
I decided to take it to another dealership and told them everything that had been done to the vehicle and after further inspection they diagnosed that it was a bad or unbalanced driveshaft, which happens to be made out of carbon fiber, which I didn't know. Well after the drive shaft was replaced the vibration was finally gone.
Fast-forward to 10k miles and i start hearing a whirling noise coming from the rear of the vehicle. I took it to the dealership and again I was told that it was normal for the Z. I didn't take that for an answer and got to ride with the shop foreman, who of course heard the noise and said it was a bit too loud to be normal. Well after diagnosing again they figured out I need a driveshaft AGAIN.
I haven't received my Z back so I have no idea if the problem has been fixed. I will give an update when I get it back maybe Monday.

Anyone having a similar problem or is it just my luck?