[Canadian Steve]

Thanks everyone for the suggestions. The last oil change was mid-July and I've only noticed the fluid on the garage floor in the last 2 weeks, so I'm inclined to think that its not related to the oil change (ie/ the filter), although I will have a look. The suggestion that it's AC condenser sounded plausible since the fluid does seem rather thin. I'm going to put a tray under the car tonight as suggested to collect the fluid to get a better sense of what it might be.