have a 92 300e 4 matic with 89,000 miles. just purchased this car. never had a benz before . engine seems very hot to the touch. car runs great. temp guage is normal, runs 80 to 100. no low coolant light comes on. my question is the plastic tank on left side of engine seems to be empty or is it I can't see the amber fluid?. I don't see a level marking in the tank. bought some mbenz antifreeze, today but don't want to add if I'm not supposed to . Do I just wait until the engine is cool and add antifreeze mixture to the tank ? don't want to overfill. []