Hello,
There are 3 causes of the floorboard flooding...
1. Sunroof drain plugged....If you've got a sunroof with a drain tube, make sure the drain tube is not plugged.
2. Windshield seal....Fix is mentioned above.
3. Plugged condensation drain on the HVAC. This usually shows during the warmer months and the condensation from the AC floods the blower motor housing. The outlet is located behind the PS pump in the engine bay....A small rubber Ell coming out of the firewall.
Later now,
Clint