I too was having problems with standing water in the floorboards.
Easy fix.....the sunroof has 2 drain tubes that run down thru the door post, we blew these hoses out (full of nasty black debris).
Once they were cleared out I have not had 1 problem with water again.
I am so happy with my car.
This car gets great gas mileage and performs great.
So happy we figured out the problem.
You may want to redesign the drain system around the sunroof.