Anyone seal up there cab corner after replacement?

[May70]

As you can see in the pics, this is my personal cab that I did a new full pan and corners on. There is a gap on the bottom side which I know will let a lot of road noise in.

I kind of like it being open for the sake of drainage (if any water does get in there). On the last cab I did, I closed that up partially. Im thinking about closing it from the top inside the cab, wondering what others have done.

Need some ideas. This has been a to-do for over a year. thx!