the window can have some moisture (fine water droplets) on it. But on the outside surface only.
If the inside of the glass is wet this is a sign the door/window seals are leaking and the door is possibly filling up with water. Open the door and give it a shake listening for any water sounds.
Oh, I note the car is still under warranty, so ASAP arrange to take the car in and have this looked into. In all the years I've had my Boxster and all the times it has sat outside in the rain, snow and ice the inside surfaces of the windows have never shown any signs of moisture.
Do not delay. If the door is getting water in it this will start to manifest odd symptoms at the door, window, which if left unresolved can turn into electrical gremlins at other areas that can really have you scratching your head.
Sincerely,
MarcW.