Well, I picked up my car today. They did acknowledge that they hear the gurgling and can duplicate it. However, they don't think there is anything wrong (no air in the system or low on fluid). They said they can hear it in other 3.0 MKZ's as well. The have reached out to Ford Engineering about this and are awaiting to hear back from them.
I am losing hope that Ford/Lincoln is going to fix this problem and I am going to have to take things into my own hands, which is absolutely ridiculous and a giant waste of my time. They way I look at it, there is a 10% chance that this functioning normally according to a Ford engineer. I think there is another 10% chance that this is design flaw that is being exposed in the real world. Then 80% chance there is air in the system, which means it would be low on coolant.
If they really think this is functioning properly and the noise falls withing spec, shame on Ford. That's just garbage engineering. We'll see. A lot of my coworkers and friends have import luxury cars, mostly Audi's, Acura's and BMW's. A lot of them question my decision to buy a Lincoln (throw in the Ford in a Tuxedo). Two of my coworkers were in my car when I started noticing this noise. They both thought it sounded like there was a problem. It's hard to argue with their logic if obvious noises/issues are throwing the Lincoln service a curve ball and they are saying it's normal.
My next steps is to wait to see if anything comes back from Ford Engineering on this (doubtful). I will also schedule dealer visit at a different dealer, explaining the situation in detail. If that fails, I am going to try and tackle this myself the old fashioned way, pop the top off the radiator, get the engine hot and fill away. I don't want to think about what if that doesn't work because it will involve me selling the car (probably at a loss) but I don't want to get ahead of myself here.