I received a call this afternoon from the Assistant Service Manager. He thought all had been taken care of until they started up the engine today--and, you guessed it--
the "mysterious" noise was still present. Needless to say, I won't be getting my GT back tomorrow as anticipated. They will keep it into next week in order to try once again to fix the problem.
Spoke with the GM late today and there are now only two options left--[u]fix the problem</u>
or [u]get me a new car</u>. Although I still have some hope, I think the chances now are no more than 50% that the noise will be eliminated.
No choice but to wait and see what happens. [:0]