+1; if it ain't dripping out, you're not losing any. Run the engine with a piece of clean cardboard on the floor under the radiator, let it run for half an hour or so to get well up to temperature and give it the occasional rev up. If there are no drips, you're not losing any. Make sure it covers the area under the front of the engine too, in case coolant is being blown back by the engine fan, and watch for steam or drips after you turn the engine off, when the fan no longer keeps the temperature down and there's a slight rise.