Tail light seals? Water in trunk

[RPDMazda]

So my jack area in my trunk is getting some water. I've already replaced the trunk weatherstrip/seal, but water is still making it's way in.

Water is coming in under where the tail light is. See video for full detail.

How do I fix this? If I were to use a caulking Gun, where would I use it?

Thanks!

https://www.youtube.com/watch?v=gld-eSEfBvw

Sorry I filmed vertically, wasn't thinking!