Had been parked in garage for a week while on vacation. When I backed out, my wife noticed a small puddle on garage floor. I took it into the dealership, and on the first trip they couldn't find anything. I took it back home and put paper underneath the car in the spot of the original puddle. The next day there were spots on the paper so I took it back to the dealership with the paper, and a description of exactly where it was puddling. This time they found the leak and replaced the water pump. This was the first major problem I have had with car (other than the horn going out a few months ago).

2016 EcoBoost Mustang - Excellent Vehicle except noticed coolant smell when exiting the vehicle. Checked reservoir and noticed there was very little fluid at the bottom. Filled and watched for two weeks. Coolant level dropped ever so slightly. Droplets of coolant could be found on the passenger side electric fan blades and a small puddle of coolant below the car formed after a week of sitting. Stealer says they pressurized the system for 2 hours before they were able to find a pinhole leak coming from the waterpump. Shouldn't be happening on a brand new vehicle.