Like a lot of people, we have had some pretty cold weather here lately. My car has a garage but it is not heated. I noticed yesterday that some coolant had leaked onto the garage floor directly under the 'drain' hole in the liner pan under the car. It wasnt much, maybe a couple of ounces. I checked the reservoirs and all looked good so I went for a long drive and had no issues. Didnt notice any more leaking. Any ideas what might have happened?