I did return the first rental
I did return the first rental/loaner and they gave me another brand new TLX with the Technology Package but one without the Advance Package and that horrid Idle Stop. Yes, I know I could disable it, which of course I did. But it was almost as if the car would default back to that mode. I know quite a few vehicles come with that now but I don't like it at all. If I wanted a Prius I'd buy one.
As for my car, the gasket on the transmission case was leaking. There was a very small separation in the seal. They identified the problem quickly. But they had my car for nine (9) days. Apparently the delay was caused because of Tech Line. The dealership's service department cannot order these parts directly. They must place the order through Tech Line and Tech Line then orders the part. Apparently Tech Line are not highly responsive. That was almost more aggravating to me than the fact that my car had an issue. Once they got the part replaced they wanted to drive the car for a couple of days to ensure that in fact was the problem and it was now solved.
Since having my car back, it drives great again and nothing is leaking. I definitely missed it when it was gone and now I appreciate more. I'm hoping this was a one off thing. As I said previously, we shall see.