Plastic outside storage

[Bjkishbaugh]

We have had this Itasca impulse for 2 years now and finally got around to asking this question.. On the outside passenger side there is a plastic storage Box. What should this be used for? All other areas are carpeted,, but this is just a plastic box. There always seems to be water in this which I think is condensing due to temperature changes. Thanks
Brandon

 

[Bjkishbaugh]

Here is a pic