I've noticed the S has been steadily loosing coolant for a little while now.....
No white smoke out the exhaust, no drips from under the engine, and I can't find any visible spot where it looks like it's leaking then dripping down onto the engine and burning off. The only part I question is that the coolant tank has quite a few stress cracks in it. I've picked up a new one but don't want to replace it until I have a better idea what else is wrong and fix it all at the same time.
I can smell a bit of burning coolant from the engine bay but that is very seldom and appears to only happen on hot days when the car has been idling for a while. I have zero oil consumption, no lose of power, and gas milage has been steady. Everything else appears to be running smooth.