Popped out to top up the screen wash today and was surprised to see the coolant level just below the min mark. It's probably been a month since I last was under the bonnet so not sure how long it's been like that. The car is just coming up for 4 months old, it's an S4. I topped it back up to the max mark. Question is : what now? Should I immediately take it to Audi or should I monitor the level closely and see if it recurs? As it's a new car I wondered if perhaps the system has just settled or should that not happen? Mileage is ~1200.