There should still be less condensation because the air in that area is now closer to the temperature of the outside air and not cab temperature which we keep cool in the summer and hot in the winter. You also wont get all the condensation from the back wall above it running down there. I cut drains in the new corners so they will be able to vent. Without the crap that will end up down there in my truck to hold the moisture they would have to last longer. I intend to treat my truck like a truck and use it as a driver and to do truck stuff. I will however screw the covers down so I can check up on how they look. What would last longer an open coffee can with organic matter in the bottom and a 3' tall piece of sheet metal standing in it or one with a top on it? There is also some outside moisture being blown into the drains but it seems to me like that would be very little.