If it evaporates, it is water. If it leaves a slimy residue, it is coolant, so if not - I would suspect either rainwater or A/C condensate. If the former, there are several drains located at various spots in the car where water can collect, and any can become clogged with debris - later slowly draining out. Shop-vac debris where you can from these areas. If the latter, mold and dirt can collect in the condensate tray, and a 'dirty-socks' smell probably means you should clean out the tray.

Steve