I had a low coolant warning when starting up for the first time one morning, and again a couple of days later. Took it to my Indie (in Indy) shop to have them top it off. It was 1/2 Gallon low, and the noticed a very small amount of coolant running down the back side of the block.
There was never a puddle or drip under the car, no smell, nothing that pointed to this. The leak is very slow and gets burned off by the heat from the block and headers/exhaust before getting to the bottom of the car to drip...
A system pressure check confirmed it. Now I'm without my X for up to 2 weeks.