The floor "behind" the passenger seat probably includes the area under the seat itself, but there is almost no clearance "under" the seat, because of the mechanism and motors.....the space is that between the seat and the storage compartments which comprise the jump seat area. The storage compartments appear dry. I have not tried to put the soft top down. If I did, I suppose I could stop the mechanism in mid-process, and look down into the top's storage boot area......this might expose a possible location for water build up. I assume this area is open to the inside of the body panels....I conjecture that water dripping off the soft-top once it saturates with water could work its way down into that area, even from the rear edge of the top, near the rear deck lid.......There appears to be no water in the trunk area, however....