Cadillac STS-V Series Forum Discussion, Question on the cooling system(s)? . . . in Cadillac V-Series Forums; Are the radiator and intercooler 100% separate systems, or are they connected and do they share the same coolant?
Is it just outside the car or also inside? You should be able to see one of the levels go down eventually if It's a leak.
When the dealer flushed mine, they left a clamp on the hose to the thermostat slightly loose. After the engine would cool back down it would leak a little. And I had coolant show up on the garage floor (and smell).
I hear you. It makes you think something is wrong, but you might just have to wait and see if it gets worse or at least shows its self to you.
The only other thing I would suggest is look around with a flashlight under the hood and from underneath. The leak might be so small that it evaporates before it makes it to the ground.
Mine had a pretty strong odor and I would only find coolant on the ground after it sat for a few days and it wasn't much. I found the leak location using a flashlight. It was just a small amount coming from the hose and only after cool down, not under full heat pressure.
But I wouldn't worry too much about it if you aren't seeing the level drop.