The low coolant light went on recently. I added about 11/2" in the reservior. Next day, after driving 20 miles, the low coolant was on again, this time down to the bottom. At no time was there an overheating issue. There was coolant puddled on the belly pan, but no evidense of where the leak was. With 7000 miles on the clock we took it to the dealer for coolant warantee work, but I am discouraged reading about all the coolant issues. Any guess? It is a 2018 Golf TSI.