Do you know where the rear drains are located? I cannot find them. The front drains work fine but I am concerned about the rear and am expecting a half a footof rain this week!More than likely the sunroof drain tubes are either kinked or clogged. Pull the car into the garage and open the roof and you will see them in the corners. Make sure there is nothing blocking them.
All sunroofs leak, but it's a matter of the tubes to drain the water away. You may even have a bad seal somewhere. Regardless, take it to the dealer to have them fix and replace the headliner.