[pestes]

Couple thoughts, do you have slide topper awnings?  If so look at the side seam of the slide on the outside to make sure the skin hasn't pulled away from the side.  On my '98 the spring on the awning over the bedroom slide got stuck and pulled the skin away just enough to create a leak.
Also when the slide is open make sure you can't see any daylight around the rubber bladder seal.  There is a possibility of leaks around the corners.
Good luck

There's no slide on this side and the focal point of the water is definitely in this corner.

The wall covering is bubbled away from the wall a bit at the very bottom of the wall where it makes contact with the carpet. I don't feel any bubbling and it feels firmly glued to the wall everywhere above the carpet level. I had figured inside the wall wasn't likely as well which is why I had ruled it out but figured I better make sure of that assumption after Richard mentioned it. The weep hole cover on this side of the window is missing but it has also been my experience that the lack of such doesn't provide an ingress point other than potentially putting water into the window track area and even then only if you have a hard spray right at the weep hole. The track area was bone dry.

There is a ZipDee awning over the window but again, the wall was bone dry and no evidence of water ever having flowed down it. And I pulled a lot of water out of that carpet, so I really do think it would have left some evidence if it flowed down the wall from the window or above the window.

We're expecting more rain later today, I'm going to go check things out when it's raining and if nothing I think I will pull a hose out and tackle this with some reproduction attempts. Just need a positive confirmation of the source before spending the money to put in new flooring.