2011 Cadillac DTS - Leak

I purchased a 2011 Cadillac DTS Luxury approximately 7/8 months ago. Beautiful tricoat pearl white, 60k miles, 1 owner (military/Coronel USMC). Couple of weeks ago parked the car & smelled hot oil. Took it back to Cadillac Dealership I purchased it from & was told there’s a leak, but they tell exactly where. The car had some factory warranty left, plus I purchased a 3 yr/36k extended warranty. There was so much oil, I was told it had to be cleaned “at my cost” in order for them to see where the leak is. Also told that they would have to remove the entire powertrain to repair the leak. After keeping my car for a couple days, I called to inquire has was the repair coming along. They told me, they had cleaned the engine & put leak finder in the system & asked me to come get the car & drive it for a few days & bring it back so they could tell where the leak is to be repaired. A couple days ago, I attempted to start by remote as I usually do to warm it up. The vehicle won’t start by remote. I went out starting the car with the key. It started, however, sounded though it was recalibrating itself. All the lights went out on the dash except for the check engine light. 1st time I’d ever seen it on. I also purchased a plan with OnStar which could diagnose the operations of the car by starting the vehicle & Pressing the blue OnStar button. So far, I haven’t got’n a report from them yet. Just did it this morning. The 2011 is the last of the big body Cadillacs. I also own a '99 Cadillac Deville (Pearl White). Very nices automobiles. And I’m a Cadillac fan. However, after this purchase, I don’t believe I’ll be purchasing the Cadillac Brand any longer. They costing ridiculously more, smaller, less room, however, more technology. At any rate, I take the car back to the dealership on tomorrow. They’re telling me the warranty may not pay for the gaskets for the repair. “Utterly ridiculous!!” Will write in another follower up after this.